In https://puzzling.stackexchange.com/review/suggested-edits/46838, I replaced a weird pseudo-3D chessboard that was hard to read with a more readable one from the replayer that chess.stackexchange.com uses. It was rejected because it "deviates from the original intent of the post" and "does not make the post even a little bit easier to read". Neither of these reasons make sense to me. The post is a pure chess puzzle that has nothing to do with the board style, so I don't see how it deviates from the original intent of the post. Given that another user previously commented the old one was hard to read, and that my new style looks much more like the usual preferred style, I don't see how the new board does not make the post even a little bit easier to read. So should this have been rejected? If so, why exactly?
It's obviously impossible to comment on a specific user's reasons, but I think generally:
Conflicts with author's intent — On other sites in the network, this is purely about the core point of a question/answer, which is usually fairly unambiguous. On Puzzling, however, things get a little more subjective because the presentation is often an integral part of a post, especially with a puzzle question. This can even extend to specific choices of wording, punctuation, layout and even things like deliberate spelling mistakes. This emphasis on visuals/presentation make it a greyer area when assuming intent, so people are often more naturally wary (even when they perhaps shouldn't be).
No improvement whatsoever — Even on other sites, "no improvement" is a bit of a misnomer, because the expectation is that edits should be relatively substantive and modify more than just, for example, a single cosmetic issue. In other words, fixing a single spelling mistake doesn't really improve a post in any real sense, even though, strictly speaking, it's more than "no" improvement.
I think your edit skates both of the above boundaries to a some degree and therefore the people that happened to review your edit erred to the "reject" side.
For what it's worth, I would've approved the edit because, whilst the edit is A) relatively minor, B) somewhat subjective & C) purely cosmetic, I think it does improve clarity without impacting the author's intent.
TL;DR — I personally don't think there's anything wrong with your edit, but it's minor enough and cosmetic enough to slip you into subjective territory. Your reviewers landed on a different side of the fence to me.