I found this very interesting too, and it actually has a great explanation! Maybe I should have even explored this side a bit deeper in the post itself.
Let's say the spiral has rotated 6000 degrees, and I'm approximating it with 100 points (one point every 60 degrees) and line segments. Well, a hexagon is nothing other than 6 points chosen 60 degrees apart from each other at the same distance from a central point, connected with straight lines. The same thing holds for a square at, e.g. 9000 degrees.
Let's say the spiral has rotated 6000 degrees, and I'm approximating it with 100 points (one point every 60 degrees) and line segments. Well, a hexagon is nothing other than 6 points chosen 60 degrees apart from each other at the same distance from a central point, connected with straight lines. The same thing holds for a square at, e.g. 9000 degrees.
Check out these images to see what I mean: https://imgur.com/a/mvIVuch