What does it mean to be British? As the Union Jack becomes the main colour scheme for Gilbert and George’s new Jack Freak Pictures, this question is waved like a red, white and blue rag at a bull.

Obviously there aren’t going to be any easy answers. This is the art duo who thrive on contradictions. They wear tweedy suits and brogue shoes and bare their bottoms for the camera; they have manners as polished as pieces of armour but they scrawl rude expletives all over their pictures; they live in a quaint little Huguenot house with a huge modern picture production plant out the back.

This new show — their first since their vast Tate Modern retrospective of 2007 — was always going to be difficult. We have seen an awful lot of their work. And those big shiny grids are beginning to feel like a bit of a cliché: not least since the artists discovered the computer and became, if possible, even more prolific. Their new series takes over both of White Cube’s London premises, at Mason’s Yard and Hoxton Square. But are they feeding a market more than the imagination?

Times Archive 1985 Gilbert and George on Broadway

From the beginning Gilbert and George have courted confrontation, aiming to shock their audiences out of complacency

• Gilbert and George: the Believing World, 1984

• Underneath the arches and down at the docks, 1970

En masse, the Jack Freak Pictures are impressive. Go into the lower gallery at Mason’s Yard. It’s like some post-modern Saint Chapelle in bright, shiny plastic. The spectator steps into a maelstrom of images; a swarm of multiplying pictures that swirl and spiral and float, creating symmetrical patterns that drift over prismatic depths. Imagine a kaleidoscope crossed with a pornographic peep show. That’s a bit what this series is like. Gilbert and George work with the gleeful energy of kids who have just discovered the joy of squashing their faces against the car window.

They gurn and grimace for the camera. They mangle their features to make hideous mutants. They make their fingers look like penises, their eyes like female genitals. It’s all in the mind of the beholder, as the title of one of the works puts it, turning the flesh of a hand into a puckered orifice. Burn in Hell, says one picture.

But just when it’s beginning to feel diabolic, the mood suddenly flips and it turns out to be rather camp. The besuited freaks look more like a pair of Bruce Forsyths.

Puerile or profound? The work of Gilbert and George is at its most interesting when it plumbs the pair’s potentially disturbing psyche.

That is what this show does. The ordinary becomes ambiguous. The repulsive becomes seductive; the solemn silly; the ridiculous terrifying. At every twist of the kaleidoscope lens, the perspective shifts. Are those military medals or a skinhead’s knuckle dusters? Is that playful face-pulling or a grimace of despair? Are those London plane trees or Dante’s dark woods?

Britain, it would seem, is a very mixed society. For all its perversity, the Gilbert and George message is actually rather PC.

At White Cube, Mason’s Yard, SW1 and Hoxton Square, N1 to August 22 (020-7930 5373)

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