Pictures based on avatars

I believe the artist of post #786206 based it on someone's online avatar, but I don't know how to tag this phenomenon. I had the tag avatar there first, but removed it when I realized that it refers to a copyright. How should I proceed?

For your reference, these online avatars are related to "アットゲームズ (@games)," Japanese game portal site of GCREST,Inc.
On this site, all avatars are called "セルフィ (Selfy)."

http://www.atgames.jp/atgames/html/service/selfy/

Thank you, though I am already aware of that (I did tag the post @games, after all). The question is, what should be the standard for tagging these?

Do we tag them as selfy? And if so, should this tag be a general tag?