I found this a while ago but I was looking at it again and just can't get over it. There are other forms of it at the Gallery of Computation. Its the Mandelbrot set but using a different kind of colouration for the different escape speeds. Its not that contrived and with this cloudy version you get see all the structure inside from the echoes of this simple construction of two, mutually recursive functions
What amazes me is how the structure inside looks so ... well, human. It almost seems like an idealized set of lungs, heart and stomach. Now maybe its just the pattern recognition in my brain going into overdrive, but this is much more than seeing a face in a cloud in the sky. There is a question of how tweaked the parameters are in the colouring algorithm, which I will have to look into sometime. But regardless, I find it a beautiful and inspiring picture. A serene reminder of the beauty inherent in mathematics if only we know how to tease it out, or to just see it.