Again, let me stress that this was done before the reign of Photoshop.  This is what was known as a “polaroid transfer.” This is a 4x5 polaroid that I pulled apart before the required time — I think it was 60 seconds — then jammed back together and waited, and then pulled apart again.   It was wildly random, and I tried to make a lot of them and this is the only one I liked.  It was a fun, but expensive, game to play.