Tuesday, May 15, 2012
Simple answer, she is not rotating, its a 2D image. One of her legs is sticking out and moves from one side of the screen to the other. The leg sticking out can be either the left of right leg: take your pick. The leg either moves from the left to the right of the screen, or vice versa.
You can either have perception of the woman rotating clockwise, anti-clockwise, or simply moving her leg from left to right never completing a full turn.
I believe its a matter of timing. Take your finger point at the foot and drag from one side to the other: that is use your finger to spin her clockwise, anti-clockwise, or back and forth.