The patterns on this monitor are the result of a camera taking a picture of the picture that it's showing. Normally, video is a one-way system: a camera gathers information and displays it on a screen. This video system, however, goes two ways: since the camera is pointed at its own monitor, it endlessly loops the image on the screen back in through the lens.
Use the buttons to rotate the camera and make the lens zoom in and out. Try putting your hand, or some other object, in front of the screen. Tilt up the mirror to make multiple patterns. Notice that even a small change can create a dramatic shift in the pattern's size, shape, and brightness.
(c) The Exploratorium, 1996