What is the mentality of people who often send "laughing and crying" emoticons?

Maybe it’s because he doesn’t know how to reply to you, or it’s used to express his mood at the moment, or he just doesn’t like chatting very much, which is just like me. Perfunctory, I don’t know what to reply, I send an ambiguous expression; I want to cry, I feel uncomfortable, it’s a bad thing anyway, but I still laugh at you; Self-deprecating, I’ve cried but I’m still laughing, so don’t laugh at me; I want to laugh, but I’m afraid you’ll be unhappy if I laugh, so I’ll add some tears.