user8157: SN 47.8 (Pali here) is translated as such:

Bhikkhus, suppose a foolish, incompetent, unskilful cook were to present a king or a royal minister with various kinds of curries:
  sour, bitter, pungent, sweet, sharp, mild, salty, bland.
That foolish, incompetent, unskilful cook does not pick up the sign of his own master’s preference: ‘Today this curry pleased my master,
  or he reached for this one, or he took a lot of this one, or he spoke
  in praise of this one; or the sour curry pleased my master today, or
  he reached for the sour one, or he took a lot of the sour one, or he
  spoke in praise of the sour one; or the bitter curry … or the pungent
  curry … or the sweet curry … or the sharp curry … or the mild curry …
  or the salty curry … or the bland curry pleased my master … or he
  spoke in praise of the bland one.’
That foolish, incompetent, unskilful cook does not gain gifts of clothing, wages, and bonuses. For what reason? Because that foolish,
  incompetent, unskilful cook does not pick up the sign of his own
  master’s preference.
So too, bhikkhus, here some foolish, incompetent, unskilful bhikkhu dwells contemplating the body in the body, ardent, clearly
  comprehending, mindful, having removed covetousness and displeasure in
  regard to the world. While he dwells contemplating the body in the
  body, his mind does not become concentrated, his corruptions are not
  abandoned, he does not pick up that sign. He dwells contemplating
  feelings in feelings … mind in mind … phenomena in phenomena, ardent,
  clearly comprehending, mindful, having removed covetousness and
  displeasure in regard to the world. While he dwells contemplating
  phenomena in phenomena, his mind does not become concentrated, his
  corruptions are not abandoned, he does not pick up that sign.
That foolish, incompetent, unskilful bhikkhu does not gain pleasant dwellings in this very life, nor does he gain mindfulness and
  clear comprehension. For what reason? Because, bhikkhus, that foolish,
  incompetent, unskilful bhikkhu does not pick up the sign of his own
  mind.

Suppose, bhikkhus, a wise, competent, skilful cook were to present a king or a royal minister with various kinds of curries: sour, bitter,
  pungent, sweet, sharp, mild, salty, bland.
That wise, competent, skilful cook picks up the sign of his own master’s preference: ‘Today this curry pleased my master … or he spoke
  in praise of the bland one.’
That wise, competent, skilful cook gains gifts of clothing, wages, and bonuses. For what reason? Because that wise, competent, skilful
  cook picks up the sign of his own master’s preference.
So too, bhikkhus, here some wise, competent, skilful bhikkhu dwells contemplating the body in the body, ardent, clearly comprehending,
  mindful, having removed covetousness and displeasure in regard to the
  world. While he dwells contemplating the body in the body, his mind
  becomes concentrated, his corruptions are abandoned, he picks up that
  sign. He dwells contemplating feelings in feelings … mind in mind …
  phenomena in phenomena, ardent, clearly comprehending, mindful, having
  removed covetousness and displeasure in regard to the world. While he
  dwells contemplating phenomena in phenomena, his mind becomes
  concentrated, his corruptions are abandoned, he picks up that sign.
That wise, competent, skilful bhikkhu gains pleasant dwellings in this very life, and he gains mindfulness and clear comprehension. For
  what reason? Because, bhikkhus, that wise, competent, skilful bhikkhu
  picks up the sign of his own mind.”

What specific thing does the word 'nimitta' ('sign') refer to above in SN 47.8?

user10100: In the same sutta, buddha said:

tathā hi so, bhikkhave, bālo abyatto akusalo bhikkhu sakassa
  cittassa nimittaṃ na uggaṇhātiฯ.

Then said about satipaṭṭhāna:

evameva kho, bhikkhave, idhekacco paṇḍito byatto kusalo bhikkhu 
  kāye (=base, object) kāyā-nupassī (=sati-cetasika) viharati ātāpī 
  sampajāno satimā, vineyya loke abhijjhādomanassaṃฯ

So:
cittassa nimittaṃ (base[=object] of consciousness) = satiya paṭṭhānaṃ (base [=object]  of sati).
The other name is kammaṭṭhāna (base[=object] of cetanā).
P.S. Sati must arise with consciousness.
I'm sorry for my first mistake answer.

user11762: I think Buddha speaks about sincere attention to the process.
Without sensitivity (sincere attention), you pretend to spend time in the practice, but do not concentrate the mind, do not abandon corruptions.
In Zen it's explained as losing the balance between calmness and alertness.
Calmness not balanced by alertness leads to states of dullness, "like a stone that uselessly soaks in water", "like dry piece of wood devoid of life".
Correct meditation should have attentive, sincere attitude.
Likewise, a skillful cook pays sincere attention to doing everything so that the food will be prepared well.

user-1: this is how i understand the sutta,
(1) A chef may know how to cook according to a cook book, but a great chef would continuously monitor and evaluate his clients according to pallets and mood of the day and adjusts his ingredients accordingly.  (where a unskilled chef would just do the same over and over without adjusting his skills)
(2) Similarly to monks (or those who practices mindfulness), a skillful practitioner would constantly monitor and evaluate results. Something that unskilled people are lacked.  Unskilled people would practice mindfulness and  (if) does not gain pleasant dwellings in this very life, nor does he gain mindfulness and clear comprehension he would not pick up on that sign that he is not gaining results. 
so sign in this context as i understand it is lack of self monitor of result and progress (there for, he would not adjust his practice accordingly.   )

8157: <p><a href="https://suttacentral.net/en/sn47.8" rel="nofollow noreferrer">SN 47.8</a> (Pali <a href="https://suttacentral.net/pi/sn47.8" rel="nofollow noreferrer">here</a>) is translated as such:</p>

<blockquote>
  <p><em>Bhikkhus, suppose a foolish, incompetent, unskilful cook were to present a king or a royal minister with various kinds of curries:
  sour, bitter, pungent, sweet, sharp, mild, salty, bland.</em></p>
  
  <p><em>That foolish, incompetent, unskilful cook does not pick up the sign of his own master’s preference: ‘Today this curry pleased my master,
  or he reached for this one, or he took a lot of this one, or he spoke
  in praise of this one; or the sour curry pleased my master today, or
  he reached for the sour one, or he took a lot of the sour one, or he
  spoke in praise of the sour one; or the bitter curry … or the pungent
  curry … or the sweet curry … or the sharp curry … or the mild curry …
  or the salty curry … or the bland curry pleased my master … or he
  spoke in praise of the bland one.’</em></p>
  
  <p><em>That foolish, incompetent, unskilful cook does not gain gifts of clothing, wages, and bonuses. For what reason? Because that foolish,
  incompetent, unskilful cook does not pick up the sign of his own
  master’s preference.</em></p>
  
  <p><em>So too, bhikkhus, here some foolish, incompetent, unskilful bhikkhu dwells contemplating the body in the body, ardent, clearly
  comprehending, mindful, having removed covetousness and displeasure in
  regard to the world. While he dwells contemplating the body in the
  body, his mind does not become concentrated, his corruptions are not
  abandoned, he does not pick up that sign. He dwells contemplating
  feelings in feelings … mind in mind … phenomena in phenomena, ardent,
  clearly comprehending, mindful, having removed covetousness and
  displeasure in regard to the world. While he dwells contemplating
  phenomena in phenomena, his mind does not become concentrated, his
  corruptions are not abandoned, he does not pick up that sign.</em></p>
  
  <p><em>That foolish, incompetent, unskilful bhikkhu does not gain pleasant dwellings in this very life, nor does he gain mindfulness and
  clear comprehension. For what reason? Because, bhikkhus, that foolish,
  incompetent, unskilful bhikkhu does not pick up the sign of his own
  mind.</em></p>
  
  <hr>
  
  <p><em>Suppose, bhikkhus, a wise, competent, skilful cook were to present a king or a royal minister with various kinds of curries: sour, bitter,
  pungent, sweet, sharp, mild, salty, bland.</em></p>
  
  <p><em>That wise, competent, skilful cook picks up the sign of his own master’s preference: ‘Today this curry pleased my master … or he spoke
  in praise of the bland one.’</em></p>
  
  <p><em>That wise, competent, skilful cook gains gifts of clothing, wages, and bonuses. For what reason? Because that wise, competent, skilful
  cook picks up the sign of his own master’s preference.</em></p>
  
  <p><em>So too, bhikkhus, here some wise, competent, skilful bhikkhu dwells contemplating the body in the body, ardent, clearly comprehending,
  mindful, having removed covetousness and displeasure in regard to the
  world. While he dwells contemplating the body in the body, his mind
  becomes concentrated, his corruptions are abandoned, he picks up that
  sign. He dwells contemplating feelings in feelings … mind in mind …
  phenomena in phenomena, ardent, clearly comprehending, mindful, having
  removed covetousness and displeasure in regard to the world. While he
  dwells contemplating phenomena in phenomena, his mind becomes
  concentrated, his corruptions are abandoned, he picks up that sign.</em></p>
  
  <p><em>That wise, competent, skilful bhikkhu gains pleasant dwellings in this very life, and he gains mindfulness and clear comprehension. For
  what reason? Because, bhikkhus, that wise, competent, skilful bhikkhu
  picks up the sign of his own mind.”</em></p>
</blockquote>

<p>What specific thing does the word 'nimitta' ('sign') refer to above in SN 47.8?</p>
 10100: <p>In the same sutta, buddha said:</p>

<blockquote>
  <p>tathā hi so, bhikkhave, bālo abyatto akusalo bhikkhu sakassa
  <strong>cittassa nimittaṃ</strong> na uggaṇhātiฯ.</p>
</blockquote>

<p>Then said about <strong>satipaṭṭhāna</strong>:</p>

<blockquote>
  <p>evameva kho, bhikkhave, idhekacco paṇḍito byatto kusalo bhikkhu 
  kāye <strong>(=base, object)</strong> kāyā-nupassī <strong>(=sati-cetasika)</strong> viharati ātāpī 
  sampajāno satimā, vineyya loke abhijjhādomanassaṃฯ</p>
</blockquote>

<p>So:</p>

<p><strong>cittassa nimittaṃ (base[=object] of consciousness) = satiya paṭṭhānaṃ (base [=object]  of sati).</strong></p>

<p>The other name is kammaṭṭhāna (base[=object] of cetanā).</p>

<p>P.S. Sati must arise with consciousness.</p>

<p><em>I'm sorry for my first mistake answer.</em></p>
 11762: <p>I think Buddha speaks about <strong>sincere attention to the process</strong>.</p>

<p>Without sensitivity (sincere attention), you pretend to spend time in the practice, but do not concentrate the mind, do not abandon corruptions.</p>

<p>In Zen it's explained as losing the balance between calmness and alertness.</p>

<p>Calmness not balanced by alertness leads to states of dullness, "like a stone that uselessly soaks in water", "like dry piece of wood devoid of life".</p>

<p>Correct meditation should have attentive, sincere attitude.</p>

<p>Likewise, a skillful cook pays sincere attention to doing everything so that the food will be prepared well.</p>
 -1: <p>this is how i understand the sutta,</p>

<p>(1) A chef may know how to cook according to a cook book, but a great chef would continuously monitor and evaluate his clients according to pallets and mood of the day and adjusts his ingredients accordingly.  (where a unskilled chef would just do the same over and over without adjusting his skills)</p>

<p>(2) Similarly to monks (or those who practices mindfulness), a skillful practitioner would constantly monitor and evaluate results. Something that unskilled people are lacked.  Unskilled people would practice mindfulness and  (if) does not gain pleasant dwellings in this very life, nor does he gain mindfulness and clear comprehension he would not pick up on that sign that he is not gaining results. 
so sign in this context as i understand it is lack of self monitor of result and progress (there for, he would not adjust his practice accordingly.   )</p>
