@Virelai I believe it searches posts that the instance you’re on knows about already, without calling out to other instances. So it’ll show you hashtagged posts from:
– the local timeline
– remote users that local users are following.
– remote toots that have been boosted or searched by URL on this instance.
@VirelaiI’ve found that searching on a small instance like booktoot.club turns up fewer results than searching wandering.shop or mastodon.social, but if I search for a hashtag on a bigger instance, then copy the URL of a toot over to the search box on the smaller instance, the smaller instance will find it the next time I search for that hashtag.