To be simple, I would say a story has to have a bit of narrative, if only "she says," and then enough of a creation of a different time and place to transport the reader.
Lydia DavisBecause I'm not writing all the time (thank goodness), my mind is sometimes pleasantly blank.
Lydia DavisMy stories are sometimes closer to poems or meditations, but often there is at least a little narrative in them.
Lydia Davis