I think the most interesting thing here is that it also works fairly well with a language it was never trained on. Apparently It’s even able to pick up on the usage of brackets (instead of fully-fledged emojis) to express emotions, which is not a thing on the English-speaking internet, as far as I’m aware. I added some examples from twitter datasets to demonstrate that.
On a separate note, maybe it’s not entirely fair to expect the model to predict the same emojis that one would expect it to, because in many cases it’s not really possible to figure the exact emotion being expressed without extratextual cues that are partially substitued by emojis (and brackets, I guess) in the first place.