The large box has holes in each end for people to insert their heads, and a half-silvered mirror in the middle. A special variac has been wired so that when the knob is turned lights in each end of the box change intensity with one getting brighter while the other gets dimmer, and vice versa. Each viewer will see a metamorphosis of his or her face to that of the person on the other side. This device was made by an art student as a class project and donated to the Lecture-Demonstration Facility.
A second hole in one end allows the action to be viewed by a video camera and displayed for the entire class, as seen in the photographs below.