Agreed. I didn't finish the article. I was hoping the author would tell me what "show, don't tell" means, why it is said, and maybe even an example. I have a guess of what it means, but as this is the first time I have encountered the phrase I'd like a concrete definition or description.

I am always trying to improve my writing and most of the books I have read on the topic of writing well have a common theme: write clearly and simply. For someone who appears to think of themselves as a writer, I did not find this writing very clear and had to re-read many sentences. I also didn't know what "mimesis" meant, and although it sounds fancy I don't think it added anything. I guess I am not the intended audience of this article.

They do get to it up front: the thesis is "show and tell" is better than "show don't tell". It's clear enough if you're the sort of person who reads lithub and has been exposed to "show don't tell" a lot. It's just another way of saying "actions are louder than words", even in a purely written medium. The idea is that sometimes you do need to tell rather than show, or do both, and there's no reason to throw that tool out of your toolbox.

I believe she's missing the point: pretty much all writers start by telling and need to be cajoled into showing. It's a bit like the advice to "never use passive voice": there are times to use passive voice, but every time you want to, think, "Who is doing this, and why am I not saying that?" If you have a good answer to that, then continue to use the passive. If not, your writing will usually be more interesting as active rather than passive. But since most writers will speak passively by instinct, phrasing a rule as absolute -- before learning how to break it -- is good pedagogy much of the time.

You can read the article and see if maybe the second half provides a good refutation to my take on it -- but otherwise I'd say you got as far as you need to in it.