Ok, I saw her spin both left to right and right to left... what do you see?
Instead of concentrating on her chest, concentrate on the woman's movement. If you see her spinning clockwise, that means you're using the right side, or more creative side of your brain. If she appears to be moving counter-clockwise, then that means the left side, or more logical side of your think muscle is superior.
At the Switched office, some of us see her going clockwise, others see her spinning counter-clockwise. At least one of us claims to see both, while another one of us opened this animation in Adobe ImageReady in order to isolate the frames to see if there's any direction-changing funny business going on. There isn't.