I'm a native speaker, and I agree with your usage. As I have heard it used, "artsy-fartsy" means "self-consciously exhibiting the accoutrements and mannerisms

I'm a native speaker, and I agree with your usage. As I have heard it used, "artsy-fartsy" means "self-consciously exhibiting the accoutrements and mannerisms of artists (or art lovers) in order to enjoy the respect accorded to artists (or art lovers), without producing anything of merit or interest (or having any taste)." It also has a faint connotation of being a step behind society, imitating the stuffy pretensions of the last (and now hopelessly conservative) generation of critics, which makes it feel slightly imperfect for this context, but only slightly. If one artist called another artist "artsy fartsy," it would mean about the same thing as "poseur." But usually it's applied by a non-artist to someone who has artistic pretensions: "Why are you being such a arrogant ass when you have done nothing to justify it?" People tolerate all kinds of pathological behavior from great artists, and they resent it when a crappy or mediocre artist tries to take the same liberties.