I don't think it's fair to consider it amputation if they're not yet put on or they can be re-attached easily.
Though the point of tags isn't to draw precision accuracy to a picture, but to direct users to pictures best fitting what they want. It's not right to not tag a picture "cum on clothes" because the cum is TECHNICALLY on her gloves or shoes
I think "amputee" fits because this looks like a girl, and it looks like she doesn't have an arm. For what we know, she could be an amputee who's just have metal shoved into her arm socket. If searchers don't want dismembered robots, they can just eliminate such a terms from their search.