Feels like the article goes through the same points in different ways every few paragraphs, so in short:

With Attie, anyone will be able to build their own custom feed just by typing in commands in natural language, the same as if they’re chatting with any other AI chatbot. To use the app, people will sign in with their Atmosphere login (meaning their login for any app that runs on atproto, which includes Bluesky). Attie will immediately understand what you’ve been talking about, what sort of things you like, and more, because Bluesky and the wider ecosystem are open systems that share data across apps.You can ask Attie questions, like what posts you might like to see or repost, and you can use the app to curate your own custom feed, personalized to you.

At launch, Attie can be used to build and view these feeds, which will later become available to you within Bluesky or any other atproto app. Over time, the plan is to allow Attie’s users to vibe-code their own social apps as well as build tools for other people.

Also, from experience, AIs are miserable to suggest feeds with any level of nuance past generic requests, somehow worse than asking in groups and forums with people that don't interpret what you asked for.