He is the picture of average. His face, his walk, his entire being is so ordinary that you'd walk past him without a second glance.
However, the average man has a secret. Whenever he touches his phone, he feels a surge of power, a rush that he never experiences in day-to-day life. His eyes gleam with malicious delight as he goes from man to troll, from decently kind to hatefully cruel.
“This is where I truly matter,” he thinks, as he types out comments that belittle achievements and amplify sorrows. If someone expresses joy, he jumps in to say it doesn't matter. If someone is proud, he tells them they aren’t good enough. And if someone is having a hard time, he urges them to consider giving up entirely.
“They can’t ignore me here,” he’s sure, a twisted satisfaction filling him as his offline mediocrity hides behind his online omnipotence.
Then he puts his phone down and the illusion shatters. The troll vanishes, and there stands the average man once again, back to being a nobody.