Space gives you a replacement icon for your time and attention sucks of choice, whether it’s Twitter, Facebook or Snapchat.

OTOH the easiest way to do this would be to have the Space app help to automate creation of Safari shortcuts on the home screen (which would be called Twitter and show the correct icon), which launches a hypothetical page in Safari like https://twitter.space.usedopamine.com which would show the pulsing animation for 12 seconds, before launching the actual Twitter.app.

What I gathered from the article is that it replaces the icons on your homescreen with its own icons. So you get several Space app icons on your home screen, each one individually configured to launch a different app, but only first after recording that your user engagement is so high that you are indeed willing to put up with a 12 second pause before reading the latest tweets and status updates.

It's hard to tell FTA, but from what I can gather it basically acts as a launcher for the social media app of your choice(s?). Pretty basic - you open the app, it does whatever pause mumbo jumbo it wants, then uses a URL scheme to launch twitter/FB/etc.

Exactly - presumably it's either a Jailbreak app or it uses undocumented APIs.