Taspo:
http://www.taspo.jp/english/taspo/Introduction.html

What's the error here?

Seconding that question. I prefer to find it myself, but I'm lost here.

Come on guys- her left leg. Try repeating her pose.

Oh, her foot's on backwards.

GordonFreeman said:
Come on guys- her left leg. Try repeating her pose.

Don't you mean the right leg?

Viewer's right = character's left.

And yeah, the foot does not turn in that direction with the leg in that pose. Anatomy error.