[Coda]

The circular ones aren't fractals, at least not by a technical definition; a fractal is self-similar such that if you zoom in on it you'll see details similar to what you saw before you zoomed in. (The first one, the red and black one, IS a fractal. You can see the repeated patterns at varying scales, and if I were to render zoomed in you'd see more of those blue-black swooshes in the same pattern.)

There is a similarity, in that they're generated by a computer program based on an algorithm, and the artistry comes in by selecting good parameters to the algorithm and choosing attractive outputs for presentation.