50-odd word short stories is actually quite an established institution in itself. Throughout the past fifteen years or so (since 1987), a California newspaper has run a short story competition labeled "Fifty-five fiction" - short stories in fifty five words, in other words. The newspaper in question is the New Times in San Luis Obispo.
Take a look at the first paragraph of this write-up. It is 55 words exactly. And notice how little it says, really. Now imagine writing a short story with the same amount of words.
It does sound quite incredible to manage to build characters, develop a story line and have some sort of punch. It is, however, quite possible, as described in the book The Writers Block, by Jason Rekulak. He includes the story of Jeff Whitmore, who won the competition one of the years: (reproduced by implied permission of the competition entry rules)
"Careful, honey, it's loaded", he said, re-entering the bedroom.
Her back rested against the headboard. "This for your wife?"
"No. Too chancy. I'm hiring a professional"
"How about me?"
He smirked. "Cute. But who'd be dumb enough to hire a lady hit man?"
She wet her lips, sighting along the barrel.