After noticing the fake nails tag, I saw it's pretty much being used in the same way as the nail art one. In some situations, it's just regular long fingernails with nail polish as well.
In most cases of art you can't tell if the nails are real or fake, and almost all of the nail lengths seen in this tag are naturally occurring in real life. I think it's a good idea to sort out the non-nail art, deprecate it and, split it into nail art, nail polish, and maybe removing fake nails when a character is obviously shown with fake nails. I wanted to come here for a discussion before doing any tag changes.