I've been here about a year but I find it hard to find a good solid art group. I don't think there is an abundance of artsy folk yet. I do enjoy !imadethis@lemm.ee however.
Lemmy is not a straight up replacement for Reddit. Reddit has a huge enough userbase to have subreddits active for lots of niche interests. Lemmy doesn't have anywhere near the number or diversity of users. On Lemmy I subscribe pretty indiscriminately to any community I think may be of interest (and would encourage everyone to post any content they think of); but still I'm mostly browsing "all", since there really isn't much content otherwise. This may also be a reflection of the fact that I've blocked all political and porn-related things and may have excluded a large proportion of the content here.