My favorite code reviews are where the reviewer only comments about trivial shit that doesn't matter, like "it would be more readable if you added a newline here" type stuff.
I was in a team one where everyone could give or receive criticism, and it was always friendly and (often) constructive - hardly ever bad feelings. Learned a lot from them, really miss that team 😒
Whenever someone asks me to review something and I don't want to just move on, I just add a comment about adding more comments to the code or ask why a var was named that way.