I’m talking about mainly third person narrators in fiction, like for example, “if you have felt/heard/seen X then…”. What is it called?
It seems like the best fit, but I’m not actually sure if that would apply either. The definition listed there is when a character talks directly to the audience, like in a Deadpool movie when he makes a joke as an aside, it seems to more apply to characters inside the story, not outside. I guess you can argue that the Narrator is considered a character in a story, but in my mind they’ve always seemed sort of nebulous and outside “the story” (with some exceptions to this). The Narrator is sort of always talking to the reader in a way (unless it’s a character specifically narrating the events to another character).
I think that might be too broad for what OP is asking, though I don’t know the answer. Their example has the narrator directly addressing the audience in a manner that acknowledges the existence of a reader for them to be addressing. Specifically they refer to a “you” which would be the reader. It’s a bit like the term “4th wall breaking” in cinema although not quite the same as that either. Just “narration” means an entity, be it a character, or the author, or voice of God is telling the story and as it says in your link, is something present in all written literary works, but they won’t necessarily acknowledge their audience, which is the unique characteristic they’re trying to identify.
I guess only OP could tell us if that sounds like what they were talking about but I don’t think that would be it either. That appears to be a device for theatre, which solves the problem of revealing characters’ thoughts when the medium would make that otherwise difficult because of the absence of a narrator. In theatre (or film or other visual mediums), a narrator is optional and if a playwright doesn’t opt to use one then it can create a problem that an aside can fix, but in literature a narrator is a prerequisite and so the problem isn’t there for an aside to fix and characters’ thoughts can be transmitted through narration freely if the author chooses and there isn’t a need for an acknowledgement of the reader in doing so.
second-person narrative mode
It sounds like it’s breaking the fourth wall. Narrators can do it.
While that’s also what I’d call it, it’s a bit of a misnomer. The fourth wall is an acting term that refers to actors not interacting beyond the invisible wall that separates them from the audience. There isn’t really any such rule that says an author can’t address their readers directly in that way.
It’s a “second person” point of view, where the narrator addresses you, the reader, directly.
Unlike in TV/movies, and sometimes in writing “breaking the fourth wall”, instead of a character turning to the audience, this shattering the fiction of a “fourth wall”, in 2nd person, it’s the narrator.
It can sometimes be a character narrating, but that usually takes on a sort of storytelling motif, where a character is telling you a story about what happened to them.
The Deadpool movies flow back and forth between all these things frequently, as an example.
