I was reading some of the comments on a small format painting Jeff's posted on his blog, State of the Art, and found the similarity to short fiction interesting. Jeff's question: can small paintings end up being Big Art? It's interesting that Jeff's assessment of small format pieces in the visual arts sounds a lot like a description and requirements for short fiction. (I didn't think of this out of the blue. Jeff starts by comparing small painted works to the Haiku form).
I think in the lit arts, short stories have been considered Big Art for a long time. They may not have been Big during the writer's lifetime, but they always seem to grow afterward. I'm thinking of Hemingway, Hawthorne, Poe, Melville, etc.
There are many great small works from painters, but it does seem to be the 6-foot canvases that get the attention. (See the post on John Constable at Lines and Colors).
Still a lot to think about in comparing visual and literary arts, but be sure to check out the complete comments to Jeff's post by artists, Tracy Helgeson and Kris Shanks. I'll give you a couple quotes anyway: Tracy Helgeson's statement that smaller works can possess "an intimacy in them that is often lost in a larger piece." (I'm not sure about the application of this to short stories and novels, because in a novel or novella an author has so much more time to get readers to know the characters). And from Kris Shanks: "I think small paintings have to work harder to have an impact." (Definitely true for short stories. In many ways writing a novel is easier than a short).