There should be a little badge or something shown in the corner of a post if the poster has set their page to only be visible to logged in users, so you can know the post won't embed in e.g. Discord without having to just try

There should be a little badge or something shown in the corner of a post if the poster has set their page to only be visible to logged in users, so you can know the post won't embed in e.g. Discord without having to just try