Yup, that is an odd one that I also noticed. It is so weird that on first viewing I didn’t even really get that they were going for a joke!
The idea that sparkling water here is generally preferred, much less the default option provided without a still alternative, is bizarre. Your comment suggests that, again, it is more of a continental thing, but isn’t true for the UK…
There’s no reason- not one that I know anyway! But tea is traditionally served with milk. Sugar is down to choice. Black tea with maybe some lemon or honey would be associated with being a cold remedy.
As I mentioned, black tea is more common on the continent, though I’m no expert!
The glass cup thing is just…odd; again, I can’t tell you why. Tea and mugs are inextricably linked. Even coffee in one of those glass cups would be rare in my view.
Sorry I can’t elaborate more!
If anything else comes up during my rewatch I’ll let you know! A big one that you may have already seen is the association of Richmond and the ostensibly working class sport of football (I know, football is super corporate and bloated with money- it is weird). Richmond doesn’t have a culture like that and would favour rugby.
I also find it strange that Richmond seems to have about 8 people living there, who all know each other and see each other regularly. It is a London borough- they’re not small!
I’m pretty boring when it comes to tea- English breakfast tea is standard, perhaps the odd Earl Grey (milk or no milk with EG, folks?).
Herbal teas can be okay. Often, however, I find the smell fruity and delicious- only for the tea to taste like slightly rank water.