There's an episode where someone is forced to watch adverts for rewards, and they're harangued if they close their eyes. I can't remember the details, but it's the concept of explicitly selling your attention that caught my eye. It seems pretty dystopian to me.

It does not sound like the same thing if you are not forced to watch ads (I think you have to opt in to receive rewards). In fact what Brave does is they replace existing ads, iirc.

Brave doesn't replace ads. You can do either, or both of:

1) Block existing ads (like any other ad blocker)

2) Opt in to Brave ads (which are served via system notifications).

If you opt in, you can get "paid" in BAT. You can cash this out (from an exchange) or donate them to the sites you visit.

Realistically, it will never be an amount worth cashing out, so I suspect most people donate it to the sites and content creators they like. Thats what I do anyways.

It's not identical, hence "almost literally", but the notion of explicitly selling your attention to advertisers is getting pretty close in my eyes.

Compared to how google treats you?

Each episode presents a dystopia based on an element of our current world, overstretched, in a way that makes you uncomfortable because it looks like we are almost there.

And actually, some episodes have been realized since their release.

In the episode “Fifteen Million Merits” the main character is fed ads on the walls of his bedroom and his eyes are tracked. If he wants the ads to stop and close his eyes in peace he has to pay a small fee each time.

this would be after <attention token> has become the new fluid currency and you've gone deep into debt by paying more attention than you had

Well, the economy in general didn't make much sense in that episode. The people "working hard just to get by" spend all day on these bicycle things that generate power, but thermodynamically there's no way they could be producing more than what it costs to feed them. Nor do I recall any sort of education or training for actual careers going on. And that's not something I can entirely ignore, when "how empty everyone's lives are" is relevant to the general plot.

Maybe they could have substituted some kind of factory assembly work, although that might have raised questions of why it's not automated.

There is an episode where you essentially directly pay with attention. Each episode is different, often inducing "mind fuck" with respect to alternative futures based on differing societal or behavioral standards