I feel that the short story is as distinct from the novel as poetry is and that the finest tales are closer in spirit to poetry than to novels.
Short fiction appears to be more focused - hand grenades of ideas, if you will. They hit, they erupt, and you never forget them when they work. Long fiction has a different vibe than short fiction: it's a lot smokier and less defined.
A short narrative is a splinter, a sliver, a vignette. It's a biopsy of the human condition, but it lacks the ability to think for itself.
A short story is a love affair, a novel is a marriage. A short story is a photograph, a novel is a film.