Maybe someone thought it should be marked as such for the standard image of the "Cupid" character with the nakedness and bow and all. But yes, I think it should just be a general tag. The only copyrights it's connected to don't have any characters *named* Cupid, far as I know. The only one I'm not familiar with is Dokutsu Monogatari, but since you're the one who uploaded that image I take it that it's not a real "character" in that either.
I changed it to General.