user11674: The 10 perceptions in the sutta are meant to be meditated upon? Aniccasaññā is then not to be understood as empirical seeing the 3 characteristics, but contemplating on impermanence, right?

user8157: In the Girimananda Sutta, there are nine perceptions (sanna) preliminary to the development of direct seeing of Anapanasati. 
The explanatory Pali word is 'paṭisañcikkhati', which means 'to think over', as follows: 

Idhānanda bhikkhu araññagato vā rukkhamūlagato vā suññāgāragato vā iti paṭisaṃcikkhati:
There is the case where a monk — having gone to the wilderness, to the shade of a tree, or to an empty building — reflects thus: 'Form is inconstant, feeling is inconstant, perception is inconstant, fabrications are inconstant, consciousness is inconstant.' Thus he remains focused on inconstancy with regard to the five clinging-aggregates. This, Ananda, is called the perception of inconstancy.

Paṭisañcikkhati
paṭi+saŋ+cikkhati 
to think over, to discriminate, consider, reflect

Also used in MN 19 and AN 3.38:

As I abided thus, diligent, ardent and resolute, a thought of sensual desire arose in me. I understood thus: ‘This thought of
  sensual desire has arisen in me. This leads to my own affliction, to
  others’ affliction, and to the affliction of both; it obstructs
  wisdom, causes difficulties, and leads away from Nibbāna.’ When I
  considered (paṭisañcikkhato): ‘This leads to my own affliction,’ it subsided in me; when
  I considered (paṭisañcikkhato): ‘This leads to others’ affliction,’ it subsided in me;
  when I considered (paṭisañcikkhato): ‘This leads to the affliction of both,’ it subsided
  in me; when I considered (paṭisañcikkhato): ‘This obstructs wisdom, causes difficulties,
  and leads away from Nibbāna,’ it subsided in me. Whenever a thought of
  sensual desire arose in me, I abandoned it, removed it, did away with
  it.

'Now I too am subject to old age and am not exempt from old age. Such being the case, if I were to feel repelled, humiliate and disgusted
  when seeing another who is old, that would not be proper for me.’ When
  I reflected (paṭi­sañcik­khato) thus, my intoxication with youth was
  completely abandoned


Similar to 'paṭisaṅkhā yoniso': 

Paṭisaṅkhā yoniso piṇḍapātaṃ paṭisevati
Reflecting properly, they make use of almsfood:‘Not for fun, indulgence, adornment, or decoration, but only to continue and sustain
  this body, avoid harm, and support spiritual practice. So that I will
  put an end to old discomfort and not give rise to new discomfort, and
  so that I will keep on living blamelessly and at ease.’
AN 6.58


11674: <p>The 10 perceptions in the sutta are meant to be meditated upon? Aniccasaññā is then not to be understood as empirical seeing the 3 characteristics, but contemplating on impermanence, right?</p>
 8157: <p>In the <a href="https://www.accesstoinsight.org/tipitaka/an/an10/an10.060.than.html" rel="nofollow noreferrer">Girimananda Sutta</a>, there are nine perceptions (<em>sanna</em>) preliminary to the development of direct seeing of Anapanasati. </p>

<p>The explanatory Pali word is '<em>paṭisañcikkhati</em>', which means '<em>to think over</em>', as follows: </p>

<blockquote>
  <p><em>Idhānanda bhikkhu araññagato vā rukkhamūlagato vā suññāgāragato vā iti <strong>paṭisaṃcikkhati</strong>:</em></p>
  
  <p><em>There is the case where a monk — having gone to the wilderness, to the shade of a tree, or to an empty building — <strong>reflects thus</strong>: 'Form is inconstant, feeling is inconstant, perception is inconstant, fabrications are inconstant, consciousness is inconstant.' Thus he remains focused on inconstancy with regard to the five clinging-aggregates. This, Ananda, is called the perception of inconstancy.</em></p>
  
  <hr>
  
  <p><a href="https://suttacentral.net/search?query=Pa%E1%B9%ADisa%C3%B1cikkhati" rel="nofollow noreferrer"><em>Paṭisañcikkhati</em></a></p>
  
  <p><em>paṭi+saŋ+cikkhati</em> </p>
  
  <p><em>to think over, to discriminate, consider, reflect</em></p>
</blockquote>

<p>Also used in MN 19 and AN 3.38:</p>

<blockquote>
  <p><em>As I abided thus, diligent, ardent and resolute, a thought of sensual desire arose in me. I understood thus: ‘This thought of
  sensual desire has arisen in me. This leads to my own affliction, to
  others’ affliction, and to the affliction of both; it obstructs
  wisdom, causes difficulties, and leads away from Nibbāna.’ When I
  considered (paṭisañcikkhato): ‘This leads to my own affliction,’ it subsided in me; when
  I considered (paṭisañcikkhato): ‘This leads to others’ affliction,’ it subsided in me;
  when I considered (paṭisañcikkhato): ‘This leads to the affliction of both,’ it subsided
  in me; when I considered (paṭisañcikkhato): ‘This obstructs wisdom, causes difficulties,
  and leads away from Nibbāna,’ it subsided in me. Whenever a thought of
  sensual desire arose in me, I abandoned it, removed it, did away with
  it.</em></p>
  
  <hr>
  
  <p><em>'Now I too am subject to old age and am not exempt from old age. Such being the case, if I were to feel repelled, humiliate and disgusted
  when seeing another who is old, that would not be proper for me.’ When
  I reflected (paṭi­sañcik­khato) thus, my intoxication with youth was
  completely abandoned</em></p>
  
  <hr>
</blockquote>

<p>Similar to '<em>paṭisaṅkhā yoniso</em>': </p>

<blockquote>
  <p><strong><em>Paṭisaṅkhā</strong> yoniso piṇḍapātaṃ paṭisevati</em></p>
  
  <p><strong><em>Reflecting</strong> properly, they make use of almsfood:‘Not for fun, indulgence, adornment, or decoration, but only to continue and sustain
  this body, avoid harm, and support spiritual practice. So that I will
  put an end to old discomfort and not give rise to new discomfort, and
  so that I will keep on living blamelessly and at ease.’</em></p>
  
  <p><a href="https://suttacentral.net/an6.58/en/sujato" rel="nofollow noreferrer"><em>AN 6.58</em></a></p>
</blockquote>
