Jendi supplied the base image of the two guys, which I manipulated heavily.
Basically, the idea was to have two strong more or less realistic figures at the top, but to overlay them with a bit mess at the bottom -- a mess in which, if you looked closely, you could pick out various figures and objects.
The fun came at the bottom -- down in that collage you can find a Nikon lens typical of those used in the 1990s (when the book was set), the obvious strip of Tri-X film, a couple of other images, a pile of clothing, and in truth I can hardly remember what all I put in there.
It was a lot of fun. For a while I was trying to find a Nikon F3, to borrow, because that's the camera the protagonist would have been using. But I couldn't come up with one in Hilo (small town!).
If I were doing it over, I think I'd pull the strip of negatives down a little bit.