You know, I acknowledge that "A Portrait in Ivory" seems to be well-written in the broad sense, and I also recognize that Michael Moorcock is a giant of genre fantasy fiction. Furthermore, I recognize that Moorcock's long-running character, Elric, who is featured prominently in this story, is held dear by many a Moorcock fan. Perhaps, I would feel the same way about the character if I had read any of the Moorcock's work that precedes this story. But, at the end of the day, I just felt that this story was dragged down by the sheer mass of the character's history. To really understand or identify with Elric's guilt in this story, you have to know what he's done. Since "what he has done", from my brief perusal of the Wikipedia entry one the subject spans over several short stories, novelettes, and novellas, many of which seem to have been written out of chronological order, that's not something I'm willing to do for this story alone. As a result, it left me a little flat.
It does, however, say some interesting things about the nature of art, specifically of portraiture, and what it reveals about the subject. Overall, though, I don't think that these observations, which arn't really all that original or groundbreaking, make the story worth it for me.