I agree it’s been done a lot. I think it only serves a purpose if it explains something about her character. It needs to convey an emotion, though. Not just be in there for no reason.
Might just be me but it’s that good old scene, right of the start of the story where a woman gets changed into her sexy underwear, gets carried away and masturbates in front of a mirror. It rarely seems to add anything to the story, it’s hugely overdone and usually really tacky.