Q:

Angled endpin on double bass?

While on Facebook, I came across this picture of a double bass that had an angled endpin:

It didn't have any description. 
What could the purpose of something like this be?

A:

This picture is a bit of an optical illusion.  The endpin doesn't bend out to the side like it appears in the picture, it really just bends straight back.  The purpose is to make the contact point with the floor more directly under the instrument, for people who like to tip their instruments back more.  Reduces the chance of it slipping.

A:

The photo must be from this no treble article.
It basically says that it changes the center of gravity of the instrument and making it lighter in the hand. The way the bass is angled, it allows the fretting hand to access the full length of the string easier, without changing the position of the instrument.

So what is that effect on the instrument and player? The effect is to change the center of gravity for the instrument, making it lighter in the hand when the bass is held more horizontally. Different players may state additional benefits, but I see this as the most significant one.
Why hold it more horizontally? To allow better left hand access to the full length of the string, primarily.

