"While the interface looks like Instagram, the app’s main twist is that, when signing up, you create an AI character, or Butterfly, that starts generating photos and interacting with other accounts on its own. There is no limit to the number of Butterflies you can create, and they are designed to coexist with human accounts that can also post to the feed and comment."
It sounds like a reinforcement learning (https://en.wikipedia.org/wiki/Reinforcement_learning) experiment where each Butterfly is an agent that is exploring how to generate feeds that maximize user engagement and by extension, ad profits.