So this clip of Joaquin Phoenix on David Letterman is all the rage today. The only question is whether Phoenix is actively participating in the joke with Letterman — who is never better than when he has a hostile guest.

But that’s the thing. Phoenix is not "hostile." He’s inert. And that’s even funnier.

So what’s the deal here? Casey Affleck is working on a documentary about Phoenix — which makes my wife very suspicious that this is all a put-on. Maybe Affleck’s (and Phoenix’s) idea is to do a documentary about the maddening absurdity of Hollywood and the promotion machine that drives it. One must consider the fact that Phoenix is notoriously uncomfortable with promoting his projects because he has utter contempt for The Machine. See his (hopefully) purposeful bizarre interview on the Red Carpet from 2005.

"Do I have a large frog in my hair? . . . Something’s crawling out of my scalp." Despite reassurances from the reporter, the actor replied, "No, but I feel it. I’m not worried about the looks. I’m worried about the sensation of my brain being eaten . . . What did you ask me?"

The alternative — that a very talented but shy man has gone full Andy Kaufman on us — is too depressing to contemplate. I noticed that Phoenix could not help but betray at least one grin for the camera, and played the straight man to Letterman’s shtick perfectly. Phoenix is a great actor, and it’s certainly within his range to play with the audience, and fans of his, for an extended period of time. And I’ll believe Phoenix’s hip-hop career when I see something more imepessive than this absurdity in Las Vegas.

The bonus for Phoenix, if this is all an act, is that he’s saving tons of money on grooming products.