I don't know if you really care or not, but because I'm using histograms a lot at work, I developed a chrome/firefox extension that shows an image's histogram when you hover over it.
I looked at a lot of pictures in this thread, and noticed a pattern in the histograms for many of the pictures (not all)
The r, g and b histograms all have a very similar shape, but are translated slightly to the right or left, and/or scaled horizontally/vertically.
Because of this, I wonder if you could get cool images by taking grayscale images, and applying some very slight random linear transformations to the r, g and b histograms.
I saw this pattern occurring mostly in pictures like>>6893143>>6893146>>6893249>>6876895>>6876896>>6877793
The attached pic is a histogram of >>6878988