Joaquin Phoenix was allegedly surprised to see his on-set rant from Joker shown on national television. The actor appeared on the Jimmy Kimmel Live! show to promote his upcoming movie on the Clown Prince of Crime. However, it seems he did not expect the late night host to unveil some private footage from the set of himself laying into Joker cinematographer Lawrence Sher. Director Todd Phillips reportedly sent Kimmel the footage to surprise Phoenix during the interview.

The "diva" rant video starts with Joaquin Phoenix in his Joker makeup and he's not very happy. "The constant whispering," he says in the video. Apparently cinematographer Lawrence Sher is whispering in the background of the shot. "Just shut the f*ck up, dude. I'm trying to find something real." Sher reportedly calls Phoenix Cher, in response to his diva-like behavior. The video goes on for quite a bit.

"It's not even an insult," Joaquin Phoenix says of his new diva nickname. "Cher, really? She's a singer, actor, dancer, fashion icon. How is that a f*cking insult?" After that outburst, the actor storms off of the set, which is something he did often, according to Todd Phillips. The director says Phoenix would often get deep into the character, but would get distracted and leave for a moment, before coming back to finish the scene.

When the Joker set video finished, Joaquin Phoenix looked visibly uncomfortable and caught off guard. "This is so embarrassing," Phoenix told Jimmy Kimmel. The video is indeed from the set since Phoenix now sports a beard and is back up to his normal weight, so it was not a bit shot for the late night audience. With that being said, Phoenix has been known to pull off stunts like this in the past, so it wouldn't be surprising to hear that this was a goof to drum up even more publicity for the upcoming Joker movie. Nonetheless, Phoenix had this to say about his on-set behavior.

"Sometimes movies get intense because you're a lot of people in a small space and you're trying to find something, so it can feel intense... That was supposed to be private... I'm a little embarrassed, I'm sorry about that. I'm sorry you guys had to see that."

Joaquin Phoenix's 2010 mockumentary found him on a promotional tour to announce he was retiring from acting to pursue a hip hop career. Not a lot of people were in on the joke, leaving many to believe Phoenix was serious through his erratic behavior. The Joker set footage could very well be an extension of this type of humor, which the actor even exhibits during the Jimmy Kimmel interview. While the footage is entertaining, it is all probably one big joke, one that the promotional department of Joker desperately needs at this point in the game for some fun and positive spin. You can watch the footage below, thanks to the Jimmy Kimmel Live! YouTube channel. The rant begins at the 11-minute mark.