Milkshakes (2021)

Martin, a young employee, has just finished the closing shift at the diner he works at. He is alone, writing out the next day's menu, when his co-worker Josh suddenly approaches him. Martin tells Josh about the mistake he made earlier; the milkshake machine overheated, and Martin was unable to deliver all 6 milkshakes to his table at once. The mistake was small, but Martin is worried and can't stop thinking about it. Instead of reassuring him, Josh feeds into Martin's insecurities, telling him that if he isn't careful, he will get fired. Josh then escalates into full on beratement as he proceeds to tell Martin how worthless he is as a human being. However, it is revealed that Josh is not actually in the room with Martin. Rather, Martin is standing alone at the menu board, whispering to himself.