A short story is confined to one mood, to which everything in the story pertains. Characters, setting, time, events, are all subject to the mood. And you can try more ephemeral, more fleeting things in a story - you can work more by suggestion - than in a novel. Less is resolved, more is suggested, perhaps.
Eudora WeltyThe first act of insight is throw away the labels. In fiction, while we do not necessarily write about ourselves, we write out of ourselves, using ourselves; what we learn from, what we are sensitive to, what we feel strongly about--these become our characters and go to make our plots. Characters in fiction are conceived from within, and they have, accordingly, their own interior life; they are individuals every time.
Eudora WeltyWhen they turned off, it was still early in the pink and green fields. The fumes of morning, sweet and bitter, sprang up where they walked. The insects ticked softly, their strength in reserve; butterflies chopped the air, going to the east, and the birds flew carelessly and sang by fits and starts, not the way they did in the evening in sustained and drowsy songs.
Eudora WeltyOnce you're into a story everything seems to apply-what you overhear on a city bus is exactly what your character would say on the page you're writing. Wherever you go, you meet part of your story.
Eudora Welty