That's how I make tea and I'm an American. Water must come to a rolling boil to brew it. But I mostly drink it iced. I'm from Long Island and every Long Islander has a pitcher of iced tea in the fridge, I don't know why. We even named a cocktail after it (which doesn't actually contain tea, just tons of booze, like five different kinds).
So, no closer to solving the mystery of Jimmy's preferred tea. Earl Grey would be my guess. Here's another photo. I think these were taken at Pangbourne but not sure. They might be from two different shoots.