Not exactly. You have to remember that language and compiler design require a LOT of work and experience to understand, and that many programmers will only see this as, frankly, spaghetti.
I think it could have used some more block comments, but that's just me.
"Toy examples" are often the result of long & deep study and practice of a subject, creating something profound which casual observers are not entitled to instantly understand. In this case, it's a very clever compiler: everybody understands this summary, and if you want "a few contextual comments" beyond the source code itself then you know where to get enough information to learn what you need to understand this.
If you don't "get it", and don't want to "get it" on your own, it's not for you.