The simple website doesn't work. Everything seems to be driven by incompatible/broken JavaScript, even what should be straight simple links. I'm too lazy to fire up Chromium to find out if it works there.
The way the artists work this very limiting and demanding medium is impressive, and probably not even easily imitated by general-purpose generative models.
You might want to take a look at https://diffusionillusions.com/ . You don't need a specialized models, little bit of traditional code for enforcing constraints on top of general purpose models can do quite a bit.
I definitely read less then 50% of GEB too, but I think I skipped to the Achilles and the Tortoise dialogs rather than the pictures :)
0: https://en.wikipedia.org/wiki/Metamorphosis_II
The way the artists work this very limiting and demanding medium is impressive, and probably not even easily imitated by general-purpose generative models.