Another example is Jarek Duda's paper on the ANS compression algorithm. A brilliant guy by all accounts, but his diagrams are... well... impenetrable. Check out Figure 4 on page 10: https://arxiv.org/pdf/1311.2540.pdf
There's lines and arrows going every which way. There's about five different concepts layered on top of each other into one diagram, with nothing to obviously disambiguate them. Like... what is the black dot between C(s,x) and D(x), and why is it pointing in random directions!?
The most extreme and stereotypical version of this style are the billboards written by some homeless people. You can probably picture it already in your mind's eye: A wall of very dense text with little whitespace or structure, and a mix of fonts and colours seemingly at random.
I had a brilliant mathematician friend who wrote like this. He would squeeze an entire semester's worth of study notes into a single sheet of paper, on one side. It was impenetrable gibberish to everyone else, but the colours and 2D positioning let him build a mental mind-map.
For people like this, if you reformat their code even a tiny bit, their mental map is invalidated, and they lose track of it completely and become upset. I discovered this (the hard way) when applying automatic code formatting tools to the codebases I mentioned previously.
Personally, I find this type of thing to be absolutely fascinating, because it's the intersection of many scientific fields but belongs in none, and hence is under-studied. There's elements of pedagogy, psychology, literacy, neuroscience, computer science, etc...
It remains an open question how we can get large groups of neurodiverse humans to collaborate on a codebase when they don't even "read" or "think" in compatible ways!
Enforcing a single style may work for most developers, but clearly not all.
PS: Even on an anecdotal level, when I was a beginner programmer I could only read a single brace and indentation style. After two decades, I can now read almost any style, including inconsistent and outright crazy indentation without even noticing that something is amiss.