There are a lot of irritating things in the “documentary” “Banksy’s Coming for Dinner” (2009, not rated) but most of them have to do with how slow-moving, dim-witted, and sycophantic people are. Especially those who are rich enough for drivers but not famous enough for name recognition, which is pretty much everyone in this movie except for Joan Collins (she was in the “Dynasty” soap opera in the 80s, bumping her irritation level up to that of the kind of person who describes her furniture as coming from “a very important gallery” or “the desk where I write my tomes”) and the infamous “Banksy” (he makes edgy graffiti art and remains anonymous).

Supposedly Banksy has agreed to come to a dinner party Collins is throwing with a handful of other semi-famous grovelers, and has agreed to be filmed, as long as his face and voice are obscured.

What director/writer/producer Ivan Massow doesn’t tell you throughout the movie is that it’s not actually the infamous, anonymous “anti-consumer, anti-war” artist Banksy, who rose to fame in the middle half of the last decade splashing wonderfully jarring, beautifully upsetting images on canvasses he wasn’t actually allowed to touch — putting a phony Gitmo detainee in the middle of a Disneyland ride, or painting imagined protest messages from England zoo animals on the walls of their enclosures or landscapes through “cracks” in the Israeli West Bank wall. The fact that the main character isn’t actually who we think it is can initially seem quite frustrating, as the filmmakers go through quite a lot of hassle to blur out the face of “Banksy” and turn his voice into the deep, distorted muddle one hears on a news magazine’s profile of a mafia insider telling all, resulting in a lot of reaction shots where it looks like his mouth is a rectangle of black and his un-subtitled quips might as well be strange engine noises. Even if we think we’re actually looking at Banksy, we can’t see his reactions to the amuse bouches, the servants, the ridiculous gift giving (hostess is given fantastic bottles of alcohol, some of which are used only to swish the inside of martini glasses, while guests are given fantastic bottles of perfume, and “Banksy” gets away with gifting a can of spray paint on a tiny easel), the pretend, “Curb Your Enthusiasm”-esque, no-real-problems-to-bother-them drama at the table (Omigawd, one of the guests arrives 10 minutes early, and another of the guests takes a phone call announced by the butler? How incredibly rude. The guest with silver shoes has to fetch him. Are they in love? But he has a girlfriend? He must apologize to Joan. Do we care? No.)

The whole movie sets the audience up to watch reaction shots from fawning D-listers who think they’re in the company of greatness (Collins says 10 minutes into the movie she’s interested in meeting Banksy because his paintings sell for a lot of money and to famous people). And, loosened up by drinks and exclusivity and probably the heat of the lights set up for the shoot, they all get a little desperate, asking Banksy to sign their (paper!?) napkins and have Joan kiss them (this is honestly more embarrassing than watching “Jersey Shore” castmembers falling drunkenly into shrubberies outside bars). You can practically see everyone’s heart rate rising as they imagine how much they can get for the sure-to-be-smudged pieces of one-ply when they get on UK Ebay.

No one ever tells us it’s a mockumentary. However, even if they did, we’re not anything closer to knowing who Banksy was. If they had actually shown the real artist-known-as, is it not his art, his stunts, his audacity, the reactions he evokes, and not the person himself, that really matters to us? (“Banksy, what do you call that haircut?!”) The movie isn’t, ultimately, about Banksy, or “Banksy.” It’s about how we react to fame, even when we are people of Joan Collins’ stature or we’re posh somebodies in London with our own drivers and still manage to be as irritating and shallow as the worst autograph-seeker on the street. Even the B-roll shots of lovely herds of deer scampering/grazing/blocking the driveway on Collins’ property aren’t entirely useless film to go under voiceovers. That’s what we’re looking at the whole time, the reaction of a herd — albeit an entirely more majestic one. Banksy may not have had a damned thing to do with this stunt, but no doubt he got the last laugh from it.