This is pretty cool. When I look at the image at this link, it seems extremely clear that the dancer is moving clockwise. But apparently, that's far from a universal read on things - in fact, it's designed to see if you are a right-brain or left-brain person. Clockwise is a right brainer, counter-clockwise is left-brain, and those who see it both ways (at alternate viewings) use both sides of their brain fairly eventy.