This greeting card was designed by Caspar and Nikolaus Schwabe in 1996 for the AHA Gallery in Switzerland.
The concept is very simple. When you open the card, you reveal the two mirrors. Just beneath them is a slot that has been cut into the card. A small number of strips of cardboard are supplied, printed with highly coloured patterns.
You take one of the cards, and feed it into the slot, so that part of the pattern is now reflected in the two mirrors, which gives a kaleidoscope effect.
Not only can you slide the strip of cardboard to and for, thus giving movement to the kaleidoscope image; by opening the card more or less, you can alter the angle between the two mirrors, which changes the kaleidoscopic image in a very fundamental way, as you will see from the video.
A very simple idea, but elegant, and very effective as well.
