The "This is the key insight -" or "x is where it gets practical -", are dead give aways too. If I wanted an LLMs explanation of how it works, I can ask an LLM. When I see articles like this I'm expecting an actual human expert
An article written by an expert is nothing like this. You might be able to get something similar out of an LLM but it's gonna take a lot more effort then was out into this.
Are you on a phone? I loaded the article with both my phone and laptop. The ascii diagram was thoroughly distorted on my phone but it looked fine on my laptop.
Maybe the page was changed? If you're just talking about the gaps between lines, that's just the line height in whatever source was used to render the image, which doesn't say much about AI either way.