Not everyone wants their focus hours in front of the whole internet. Open Settings and switch on Private account, and Roomie works differently for you from that moment.
Following you now takes a request. Someone taps Follow, the button turns into Requested, and you get a notification. Waiting requests sit in a new Requests tab on the Notifications page, each with Confirm and Delete. When you confirm, they hear about it and start following you. When you delete, nobody is told.
Your sessions reach your followers' Home feed and nobody else's. They no longer show up in Explore, and the Live rail only shows you to people who follow you.
Anyone who isn't following you sees a short profile: your name and photo, your follower and following counts, and your total focus time. Where the heat map and library would be, they see This account is private and a prompt to follow you, or a note that their request is waiting. Visitors who aren't signed in are asked to sign in first.
Everyone who already follows you keeps following you, and they carry on seeing everything. If you go public again later, everybody who was waiting is accepted at once, so the switch is safe to flip back and forth.
Public focus pages are separate and stay exactly as you set them: a page you chose to publish is still public, whatever your account is set to.