I don't entirely follow...

Most of the diagrams in this article are SVG files. Yes, you can look at the source (a big pile of numbers), but that doesn't say how they were created.

I realize that a lot of this author's other articles have animated WebGL stuff, and the source code is illuminating, but not so much here, unless I'm missing something.

You are right, my comment applies to other articles by this author but not this one.