Oh man, I forgot about that! Guess I have to go rewatch it now.

It’s a joke referencing: https://en.wikipedia.org/wiki/PC_LOAD_LETTER

When I open the app, the top-lefr hamburger icon lets me select my feed, which can be: Subscriptions, Local Posts, or All Posts. I have mine set to subscriptions, and I only see the communities I’m subscribed to. This setting persists in the app every time I open it.