when people tag posts "unreality" it's a signal to people who struggle with discerning reality that a (likely scary if believed to be true) post is not real even though it's written as if it was. it's also a filter tag so those people can opt out of seeing posts like that entirely. many people who rely on the unreality tag are psychotic and struggle with paranoia alongside (or because of) the struggles discerning what's real. posts that these people interpret to be real can lead to incredible distress and compulsions.
when someone tags your post "#unreality" and you screenshot the tags and say "what are you talking about? this is real" because you consider the post easy to discern as not real and find this joke funny you're actually just causing paranoia for people who now feel like they can't trust the unreality tag. not everyone has the same reality discernment skills as you. what's "obviously" a fictional story to you may not be obvious to other people.
I don't think most people make this joke maliciously. I think most people making this joke don't even realize why the unreality tag exists. anyways, if you've made this joke or have the urge to make this joke then consider not doing that.
