Maybe you've already seen these before, but essentially, they're suppose to tell you if you're right-brained or left-brained. Sorry to break it to you but its a load of bull, however the illusion is extremely interesting. I've always seen it as rotating clockwise, and never knew how people can see otherwise. But this picture, altered a bit to trick your brain, helps you see "both sides of the story." Essentially its the features of the silhouette highlighted a certain way to give the viewer a sense of depth and perception, but when the features are reversed, a new perspective is revealed. Really cool.