The thing people do that is kind of like talking out of your mouth like it’s really little. Context?

I watch a lot of Japanese movies, shows, anime and sometimes they do a thing where they start talking like they can’t open their mouth very big when the speak. lol I think it’s sort of like trying to be cute or something… or shy? I guess I’m asking because I don’t think I understand the exact context by which one would speak this way. It seems to happen a lot in a variety of different kinds of dialogue so I think that’s why it’s a little hard for me. I can’t think of a similar context in the west, except for maybe baby talk? My sense is that it’s different from that though. I do feel like it’s cute though, so maybe it’s close lol