This is Photoshop Inception. They say when you reach limbo you find yourself in an HDR program.
Image credit: Photoshop art about Photoshop art by scott_bl8ke
Yeah! 3D computing.
This is known as the droste effect. Frequently done by M.C. Escher.
loved the limbo part :)
Congrats, you triggered a whole half hour adventure on wikipedia for me.