Do Rich Yanks Dress Better than Rich Brits?

The Telegraph's Harry Mount suggests the British rich are a bit "shabby"--or at least they don't dress as well as their American counterparts. Mount uses a photo of Prince Harry falling off his horse at a New York polo match to illustrate his point:

please look at the man in the centre of the picture above, in the middle of the crowd, rushing to take a shot of the falling prince. He will have taken his time laying out his clothes on his bed that morning (a bed in the most chi-chi part of the West Village, I'd say; possibly the Upper East Side): cream trousers, black belt, pink shirt, studiedly open at the top three buttons, blue linen jacket.

Then he insists that there are two other people in the picture who exhibit typical "British shabbiness":

What nationality do you think the two men on the right are? There are a couple of clues. The one on the left, in a green T-shirt, is clutching a bottle of the free promotional champagne; the other is drinking a glass of the stuff, and wearing an England shirt.

The "cream trousers" and "studiedly open" dress shirt are what the American and European "super-rich wear these days," he says, but the Brits apparently prefer T-shirts. Convincing? Is there a noticeable contrast in the way American and British elites dress?