Here's another creation by the extremely clever artist Osamu Kanda. The piece is titled Face. The body of the robot-like figure has a cube inside on which a small face is depicted.
When button on the front of the machine is pushed, a hidden motor causes the the robot to spin on its pedestal. Upon making a full revolution, we find that the face on the cube has changed expression! The figure has three different expressions in all. If you watch all the way to the end of the video, you'll get a small hint as to how this magic is accomplished.
See more pictures of Osamu Kanda's piece Face on his web site.