I've never liked the idea that you must never tell an artist what their work reminds you of, because sorry sometimes it's really fucking clear someone really likes Evangelion or whatever.
But it can't be the ONLY thing you say to them. You gotta actually talk about the work in front of you not just hold up the OTHER work
it feels silly to talk around it, that's all
Oh the one time you must never tell them: if the comparison is going to be (or come off as) derogatory. For example if you compare a painters work to Thomas Kincaid, that's going to hurt. Just keep that shit to yourself.