This is just a random experiment: the gradient from one component of noise is rotated 90 degrees and used to displace the next component in a sum of three terms, and the result is thresholded (with proper antialiasing) to create a swirling mix of two colors.
Now, this shader in particular is probably not good for much, if anything, but we hope it shows that you can do weird and wonderful things with the gradient, even with shaders that require only modest amounts of GPU power.