Early in his bold and vexing new reality show, Jerrod Carmichael hears a knock at the door and opens it to find a very tall man in a ski mask and goggles just standing there. He pauses to process, then concludes: “This makes sense.”

Most viewers probably thought: Really? But certain comedy fans would come to a different response: Welcome back, Bo Burnham.

Sure, we don’t know it’s him. On “The Jerrod Carmichael Reality Show” (HBO), this lanky masked man is referred to as Anonymous and his voice is disguised. But if this isn’t Bo Burnham, it’s a pretty good impression — or at least, one of him dressed to rob a bank.

Burnham has been conspicuously quiet since rocketing to superstar status by producing one of the signal works of art about the pandemic, the 2021 musical comedy “Inside.” He dropped out of a role in a TV series and appeared in no new specials, movies or live shows. Except for “Inside” outtakes, he hasn’t shown up in any new work — until, possibly, now.

Starring in three of the eight episodes, Anonymous comes off like a performance piece, half-abstraction and half-person, with no background, identity, face. He stands out more by revealing little, which is only one of the ways he’s in opposition to Carmichael, who is seen doing stand-up in short clips and having thorny, difficult conversations with his loved ones. Anonymous plays a crucial role, an exasperated ombudsman, picking apart the entire enterprise from the inside, providing a critique of its authenticity and the perils of performing for an audience.

These are hallmarks of Bo Burnham’s work dating at least to his far-too-overlooked MTV sitcom, “Zach Stone Is Gonna Be Famous,” a satire of reality shows.