Laundromats keep strange hours, with many staying open, un-staffed, overnights. For that reason, it seems to attract a rather wide and varied clientele. Being one who does his own laundry at places like the one depicted in the following video, I can tell you honestly, sometimes you are inevitably in there with a weirdo, especially late at night. There is this moment where you realize it, and are not quite sure what to do next.
Fewdio addresses this fear in another awesome horror short, The Laundromat.
Bet you didn't see that twist coming.