|Probably not exactly fair use.|
I think that this is an insult whose day has come again.
The concept of the poseur is superficially related to the concept of authenticity, but without any of the troublesome ideological overtones. "Authenticity," after all, is a purely artificial concept. (As Ernest Gellner's readers know, the "authentic" Ruritanian is the Megalomanian who behaves the way actual Ruritanians would act if only they were enlightened.) But a poseur, by contrast, is a fake. He knows just enough to skate by in casual conversation or the everyday presentation of self, but he really doesn't have any claim to the status he claims for himself. Accordingly, anyone can be a poseur in any dimension. You can pose as a comic book fan, and even pass as ones to most people, but five minutes of conversation with someone who knows what they're talking about will reveal you as a poser.
The greatest asset of resurrecting the "poseur" tag will not be in adding a new insult to our quiver, but in deterring behavior that smacks of poseurdom. All of us feel the temptation from time to time to pose. But if we're more afraid of being caught out than we are tempted of putting on a false front, then we may be able to overcome the Dunning-Kruger effect.
So let's all start acting like middle schoolers again. Sometimes, kids can be just cruel enough.