NNescio said:
I agree that Robin's ones are actually her hands.
Though it is definitely going to be a source of mistags (because they tend to look like gloves at first glance) and have to be gardened from time to time. Nothing much we can do about it, though having a separate animal_hands tag might help in hinting to people not to put the gloves tag back on after they are removed.
I'd say if one isn't sure, then the "hands" should be tagged with neither. And examples that are depicted as clearly gloves should be tagged gloves, never mind the actual canonicity.
I'll try to keep an eye on Robin's newly added art. Also for Diona I tagged post #4597794 with animal hands, since it looks like the cat hands she has in her official art. Hopefully that's fine, otherwise I apologize. I might have jumped the gun there, I did it before it was brought into discussion.
Updated