Infinitely deep illustration

I can guarantee that you'll be stunned by this illustration. It's a Flash animation and after some loading you'll be able to use the mouse to go deeper and deeper into the picture. I've never seen anything like this on the Internet before.

How do they do that? I'm curious. The picture is fuzzy but I still think a lot of attention has gone towards the details in the pictures. Salvadore Dali would probably enjoy this illustration if he was alive today.