Turn a picture like this into a jigsaw puzzle, and then let people place the pictures. At the start of the game only release a few pieces. As pieces are placed correctly together, spawn new pieces that fit, somewhere, on the border of the part of the puzzle already completed. As the puzzle grows, players can zoom out (like the linked artwork).
Let many, many people work on the same puzzle and maybe have an ongoing chat for collaboration "let's all work on the part in quadrant 23 (or something).
It loops around an array of 48 (hand-drawn?!) images, using 4 images at any given time. The images and the base scale factor are based on an incrementing 'z_position' value. It copies each of of the four images in to an HTML5 canvas so the outer 25% is a straight up copy of one image, then 50-75% is 0.5 scale copy of another image, then 25-50% is a third image at 0.25 scale, and the centre 25% is the fourth image at 0.125 scale. All the effects are CSS filters applied to the canvas element.
It's surprisingly simple for such a cool effect.
It's awkward to explain. One problem to wrap your head around is that the series of images you create by zooming out previous images has to played in reverse.
I could imagine programming a shallow random-generated fractal generator creating series of images and then the infinite zoom would be really infinite, and this would be even easier than the loop.
I haven't looked at the images, I assume then that they are specially made for that effect? (because I can't see the images fading one into another)
Reminds of the powers of 10 video: https://www.youtube.com/watch?v=0fKBhvDjuy0
My only critique is that I wish the creator hadn't used JPG images - there are clear compression artifacts that appear towards the edge of the screen as one image transitions to another.
Or at least I interpreted zooming as the ability to direct it.