I'm enjoying reading these. just remember: flash fiction isn't a form with any specific length requirements (not all publications and institutions consider it a form of its own to begin with), so they can exceed "Hemingway's" example by quite a lot.
consider these Lydia Davis stories, for example. they're quite good, and longer. these are longer still.
that's not to talk anyone out of the fortune cookie-sized stories, as those have a wisdom of their own, but adding some length could be very freeing too. a kind of freedom is, I think, what appeals to many about writing flash fiction.