Coderwall forces you to upload an image, then it "hipsterizes" it (their words, not mine). From what I can tell, this involves significantly reducing the size of the image, increasing the saturation and local contrast, and then stretching and blurring it.

As a photographer, this is quite annoying, because it's hard to predict what something will look like. I'll try to find a photograph of mine that'll stand up to being "hipsterized" better.