My photos here do not really do justice to the 3-d effect of the layers of images.  Each layer is cut out and glued to a piece of cardboard.

Behind the screen that the soldiers are watching is glued a piece of polarized plastic.  By this I mean that it has a pattern of parallel grooves in it.  When another piece of this plastic is placed on top of it and rotated a visual effect is created not unlike a television coming in and out of tune.  I used a tiny motor from a video projectors zoom lens to build a mechanism that produces this effect mechanically.  A multi colored LED then illuminates the screen completing the illusion.