The link references at the bottom have some more detail on the structure. For example, the N-Category Cafe talks about how the dragon curve shows up at the edge

The link references at the bottom have some more detail on the structure. For example, the N-Category Cafe talks about how the dragon curve shows up at the edges [0]. There are other gross level symmetries due to the symmetries of the Littlewood like polynomials involved. For example, if $p(x)$ is a Littlewood-like polynomial, then so is $p(1/x)$ etc. I think the "holes" that show up on the unit disc because of the factors of the degrees of certain polynomials. If I'm not mistaken, the holes follow a Farey sequence [1]. I wrote a little blurb about it but it's still incomplete and haphazard. One thing I'm still curious about is how quickly the holes diminish in size. [0] https://golem.ph.utexas.edu/category/2009/12/this_weeks_finds_in_mathematic_46.html https://golem.ph.utexas.edu/category/2009/12/this_weeks_find... [1] https://en.wikipedia.org/wiki/Farey_sequence https://en.wikipedia.org/wiki/Farey_sequence [2] https://mechaelephant.com/dev/Littlewood-Polynomials-Notes.html https://mechaelephant.com/dev/Littlewood-Polynomials-Notes.h...