In the climax of the episode, the real John is finally able to shut him up by putting a sword through his monitor. He appears only on a TV screen, he's always wearing a suit, always standing against a dark background studded with neon blue tubes, and sports a noticeable Headroom-esque stutter and a warped sense of humour.
Coulson even directly compares his situation to Max Headroom.
The background of the screen is a near copy of Max Headroom's, Coulson wears a suit, and he speaks glitchily.
