Stretchy arboreal tarantulas

[Syngyne]

Whenever I see a picture of an arboreal tarantula, it's usually flattened out, with its front legs straight in front of it, and its hind legs stretched out behind. Why do they do this? Is it so they can see past their legs?

 

[kyrga]

My guess would be that because some (or all? I'm not sure) aboreal Ts build tunnel webs, and don't have room to stretch out side ways, so they stretch their legs forward and back.

 

[Bob Bohnet]

I would guess that being flattened out would give more surface area contact with the scopula, and being stretched out length-wise from being on narrow branch's?
Just some guessing.

 

[Gesticulator]

Arboreals like to strut their stuff for the camera? They tend to be "leggier" as their body structure is a bit different than terrestrials. However I have seen many a Grammostola stretch as well.