If you can dimly remember the concept of refraction from high school, you're doing better than most. Perhaps if you'd been taught using this video as an example, you'd have paid more attention.
Called Prismatica, the artwork depicted in this video uses pyramid-shaped crystals fixed to an LCD screen to work its magic. The LCD screen is illuminated using a programmed animation, and the patterns are mapped and transformed by the prisms as they refract the light. Depending on where you stand and the lighting in the room, the piece looks different. From where I'm standing, it sure is beautiful. [Prismatica]