I created this a long time ago and totally forgot about it, but still think it looks pretty cool. This is an outward-moving kaleidoscope overlaying in inward-moving one with the upper animation's blend mode set to burn.
The base image for the kaleidoscope is actually a photograph of some kids from our church kids that my wife and I took to Universal Studios in Orlando. They were standing beneath the Jaws shark statue! Who woulda thunk that such a photo would create such a cool animation?