You can set the screen saver on Apple TV to show curated memories, shared or personal albums, or photos from favourites or recent activity in the Photos app.
Go to the Photos app on Apple TV.
Navigate to Shared Albums or Albums at the top of the screen.
Select a shared album from the Shared Albums category or an album from the Albums category, then select Set as Screen Saver and confirm.
Go to Settings on Apple TV.
Go to Screen Saver > Memories & Slideshows, then do any of the following:
Choose which memories to include: Select Memories, then choose All Memories or Favourites.
Choose which albums to show: Select Albums, then select Favourites, Activity, or one of the shared albums from the list.