How does the map operation from WebClient do the mapping?

Given that example:

client.get()
        .uri("/quotes").accept(MediaType.TEXT_EVENT_STREAM)
        .retrieve()
        .bodyToFlux(Quote.class);

When i want to convert Quote on the fly to BetterQuote for example:

client.get()
        .uri("/quotes").accept(MediaType.TEXT_EVENT_STREAM)
        .retrieve()
        .bodyToFlux(Quote.class)
        .map(this::toBetterQuote);

The question here is:
Will all Quotes be fetched from a given API and then (if all are there) the map() will happen?
Or does the map() starts to happen immediatly when the first Quotes are coming in?

So will this iterate only once the whole Quotes?

Iterable<BetterQuote> betterQuotes = client.get()
        .uri("/quotes").accept(MediaType.TEXT_EVENT_STREAM)
        .retrieve()
        .bodyToFlux(Quote.class)
        .map(this::toBetterQuote)
        .toIterable();

Whereas this iterates twice?

Iterable<Quote> betterQuotes = client.get()
        .uri("/quotes").accept(MediaType.TEXT_EVENT_STREAM)
        .retrieve()
        .bodyToFlux(Quote.class)
        .toIterable();

Iterable<BetterQuote> moreBetter = betterQuotes.map(this::mapToBetterQuotes)