Delta

This is the actual answer, the other replies are over thinking it. There’s a gradient on his face ffs

Skill issue

If you do want to learn more, Innuendo Studios did a 6 part series called Why Are You So Angry? that’s pretty short (most episodes are ~10 minutes) but goes into the details

Edit: part 4 (An Autopsy of Gamergate, 18min) is probably the best summary, but the entire series is worth a watch if you have the time