I just had to do a flipblend polar coordinates thing to something I did for the layers side challenge. (Heck, I have to do these things to just about everything - very distracting when I should be doing other stuff.)
Looks like a "regular" photo taken through the bottom of a glass or something to create distortions. It "feels" like an impressionistic version of a gritty, urban photo, and I think I like it even more because of that element of realism.