Tom Sutcliffe: Who do you think you're looking at?

The week in culture

(WADSWORTH ATHENEUM MUSEUM OF ART/ART RESOURCE)

It's always surprising to find how long a history the newfangled has. Take "newfangled" itself, as one example. I remember once being surprised to find the word in Jane Austen, but the OED's first citation actually comes from as far back as 1496. I guess that's fairly obvious, when you think about it a bit. Fangling, whatever it is, somehow doesn't sound like a post-industrial process. But the larger point still stands. A lot of the things that we think of as sharply and distinctly contemporary turn out to have been around for ages.

I encountered an example just the other day, walking round Dulwich Gallery's new exhibition on Salvator Rosa – a painter who could, almost literally, be said to have put in the foundation stones for English romanticism and the English sense of the picturesque. The exhibition mostly consists of Rosa's landscapes – thrillingly wild assemblies of gnarled rock and boulders, lightly garnished with with banditti and splintered tree-trunks – though it also finds space for some of his paintings of occult meetings, a kind of 17th-century equivalent of Hollywood horror films, packed with deliciously terrifying visions of the devil and witches. But it was the portraits that prompted that sharp, missing-step, feeling that the past is much closer to us than we sometimes assume – and particularly two portraits that have been hung as companion pieces – here titled as Philosophy and Poetry.

What feels modern about these portraits is their contempt for the viewer. In one a young man with long, dark, hair looks at us sardonically, his expression underwritten by the placard in his hand, which bears the motto "Aut Tace, Aut Loquere Meliore Silentio", a Pythagorean tag which translates as "keep silent, unless your speech be better than silence". "Shut it", in other words – a bracingly aggressive communication which isn't softened by the man's expression.

In the other painting a young woman with a headband of blue cloth and bayleaves turns to look over her shoulder at us, as if interrupted – her expression just teetering on the edge of irritation. It isn't open contempt yet, but there's a strong sense in it that she's turned her head for something negligible – us – and away from something far more important – whatever she's writing with the quill in her hand. Together the pictures deliver exactly that little kick of disregard that is a feature of so many modern photographic portraits.

Laura Cumming, who writes illuminatingly of the former in her book A Face to the World, actually describes this as a "rock star pose" – which is another way of capturing its recognisable modernity. She accepts the long tradition that it's a self-portrait of Rosa himself (a tradition the Dulwich curators are inclined to dismiss) and reads it as a performative pose, the adoption of a sexy, bad-boy aloofness which is calculated to enhance his mystery and his appeal. And, whether it's Rosa or not, that's certainly the quality it has; the seduction of the character who will be hard to seduce and who isn't interested in your good opinion. If you want to see this look nowadays, open any copy of Rolling Stone magazine, or any fashion glossy, and you can see it's equivalent – the loftiness of those who know they're worth the climb. There are countless portraits that look back at you – implying a kind of reciprocity of gaze – and there are as many that look out at you, as if the picture is a container for a psychology. But these two unmistakably look down at you. I'd always assumed that it was a peculiarly late 20th-century expression, this – the celebrity sneer which helps its bearer to maintain the illusion that they aren't selling anything, and aren't dependent on our goodwill as consumers, but are actually romantic heroes.

But here it is, straight out of the pages of GQ and onto a canvas from 1641. Did Rosa invent this look, or does he simply record its arrival as another way of confronting the world? I don't suppose one could categorically decide either way, but it was somehow comforting to find that arrogant cool had such a long back-story.

Why it's all in the timing for today's performers

I wonder if the pendulum of fashion will ever swing back when it comes to the length of plays? I went to see Anthony Page's Design for Living the other day – mildly startled to discover that it contained two intervals and ran for something over three hours. Quite a few of the generally approving reviews also mentioned its length as a drawback, almost as if it was bad manners to keep an audience in for so long. And yet, when I first came to London in the late Seventies it was commonplace for productions to have two intervals and a three-hour stretch was utterly routine. To have grumbled about the fact would have seemed distinctly odd, and there was even a certain premium in theatrical marathons, such as David Edgar's adaptation of Nicholas Nickleby. The steady reduction in the average length of plays over the following decades can't simply be a matter of degraded attention spans either, since the average length of a movie has been steadily increasing over the same period. And given that this is an alteration in fashion, there's nothing to say that it won't change again, just like skirt lengths but on a far longer periodicity. Reading about a new adaptation of The Great Gatsby, shortly to open at the Public Theatre in New York, I wonder if the shift has already begun: it runs for eight hours, with two intermissions and a dinner interval.

Come fly with me, let's fry away

It's one thing for John Prescott to be tweeting his approval of the singer Rumer – one assumes he has quite a bit of spare time on his hands these days. But it's a bit surprising to learn that the Prime Minister is a big fan of Angry Birds, a lethally addictive and utterly pointless iPhone game that requires you to catapult cartoon avians at a variety of structures, notionally built by egg-stealing pigs to protect their loot. I'm currently in an Angry Birds recovery programme – and I know how hard it can be to stop at just one or two attempts. So was the Prime Minister serious when he said he'd paid for the full version and if so when on earth does he find time to play? More to the point, perhaps, given that the satisfaction of the game consists entirely in destroying elaborate but fragile edifices (the more damage you do the higher your score) should we regard his enthusiasm as a symptom of dangerous underlying impulses or a harmless release of desires that might prove much more lethal if applied to Post Offices, say, or the NHS? And, if he does have time to kill, even in that most demanding of jobs could he – or Number 10's Angry Birds Strategy Unit – give me any tips on clearing level 8-10 with three stars?

t.sutcliffe@independent.co.uk