Comment by InsideOutSanta

>choosing the glyphs according to purely graphical concerns, "what would look nice here", lines being too long or too short, avoiding repeating sequences or, to the contrary, achieving interesting 2D structures in the text

I wouldn't assume that the writer made decisions based on these goals, but rather that the writer attempted to create a simulacrum of a real language. However, even if they did not, I would expect an attempt at generating a "random" language to ultimately mirror many of the properties of the person's native language.

The arguments that this book is written in a real language rest on the assumption that a human being making up gibberish would not produce something that exhibits many of the properties of a real language; however, I don't see anyone offering any evidence to support this claim.