a thing mastodon has that the bird site does not Show more
Mastodon doesn't have that, Mastodon is a software.
The instances in which you are/which you interact with may have that either as a rule or an spontaneous way of life, and this is a good thing indeed.
What Twitter hasn't is federation, and federation is what allows instances to behave their way without bowing to advertizing overlords.
Follow friends and discover new ones. Publish anything you want: links, pictures, text, video. This server is run by the main developers of the Mastodon project. Everyone is welcome as long as you follow our code of conduct!