This photo pictures a novelty item that consists of a rectangular box with two mirrors on its top and bottom sides. The top mirror is half-silvered allowing one to see through to objects behind it. Several lights are embedded in the vertical wall of the box. The parallel arrangement of the two mirrors creates multiple images which appear to be stretching to "infinity".
For more information about the physics of multiple mirror systems, visit The Physics Classroom Tutorial - www.physicsclassroom.com/Class/refln/index.cfm.