> Converting the idiomatic math into non-idiomatic words would not be an improvement in clarity in this case.

You seem to be missing my point. It's not about improving "clarity" about the math each line is doing -- that's precisely the kind of misconception so many people have about comments.

It's about, how long does it take me to understand the purpose of a block of code? If there was a simple comment at the top that said [1]:

  # Calculate top-left point of the bounding box

The original assertion that "This code is so literate, so easy to read" is demonstrably false. Naming something "pt" is the antithesis of literature programming. And if you insist on no comments, you'd at least need to name is something like "bbox_top_left". A generic variable name like "pt", that isn't even introduced in the context of a loop or anything, is a cardinal sin here.

[1] https://news.ycombinator.com/item?id=46366341