For example in the screenshot (twitch clip), if you want to share on reddit you click the reddit button, but what button are devs supposed to put to share in the fediverse? Do they pick an instance of their choice?! Is this a weakness of a federated platform or what?
You are not logged in. However you can subscribe from another Fediverse account, for example Lemmy or Mastodon. To do this, paste the following into the search field of your instance: [email protected]
A community to talk about the Fediverse and all it’s related services using ActivityPub (Mastodon, Lemmy, KBin, etc).
If you wanted to get help with moderating your own community then head over to [email protected]!
Rules
Posts must be on topic.
Be respectful of others.
Cite the sources used for graphs and other statistics.
Ultimately, some user account has to create a post to share something. Each account is tied to an instance, so: Yes.
Through federation, the post is visible to other users on other instances.