Kokichi Sugihara, a professor at Meiji University in Japan, became famous for his ambiguous cylinder illusion when he took second prize in the “Best Illusion of the Year” contest.
The object he created looks different when viewed from the front and back, yet deceptively looks symmetrical. The result is that the object looks very different in the mirror than you imagine it should. What appears to be a cylinder, relects as a square. Turn it around, and the object itself seems to turn into a square while its reflection turns into a cylinder. It’s very strange to watch the transition. I made a video here:
My son received a version of this as a gift in his science class (the blue object above). This version has four cylinders stuck together and the reflection looks like a star. Turn it around and it reverses. The object itself transforms into a star and the reflection turns into four cylinders.
Robert R. Gray 