The New York Times, which refers to the show as a "British Jersey Shore," explains it best:
Not...everyone would see the show's arrival here—a kind of homecoming, given its roots in MTV reality spectacles like The Hills and Jersey Shore—as a cultural milestone. The Only Way Is Essex...has been reviled in Britain as a pestilent example of depraved New World values and a leading indicator of the apocalypse.
...If it were on television, and you happened to tune in while channel surfing, you would not be able to tell right away, and perhaps not for several minutes, that you were watching a nonfiction show.
Dropping any pretense that the action has been accidentally captured on camera—an opening title announces, "the people are all real, although some of what they do has been set up purely for your entertainment"— Essex is staged, shot, and lighted the way a drama series is, from the multiple camera angles to the too-good-to-be-true reaction shots to the choreographed entrances. No one wanders through a shot accidentally in Essex. Everything extraneous has been removed from the frame, just as in fictional filmmaking.
More centrally, the beach-house dodge—ostentatiously creating an artificial environment within which you then pretend that what's happening is real—is dispensed with. The characters in Essex enact normal lives, if wildly shallow and materialistic ones, in such an obviously artificial way that you find yourself not giving a moment's thought to what's real and what isn't. Which somehow makes it seem more authentic, rather than less.
The Only Way Is Essex has the familiar narrative rhythms of a reality show (nothing much actually happens), but every scene is so strikingly framed, composed, and edited that you know there were multiple takes and a lot of producer-meddling going on. The effect is a bit disorienting at first, but once you're sucked into the vapid world of these pretty people it's really difficult to leave—which explains why I've lately been up until three in the morning. I mean, I was completely sold when one of the characters hesitated in her vajazzling duties by explaining, "I'm not good at art." That solid gold comedy, people!
Here's a vajazzling clip:
And here's a trailer for the series—the first two seasons are on Hulu, and the third season in airing in the U.K. now: