Create a photo screen saver on Apple TV
You can set the screen saver on Apple TV to show curated memories, shared or personal albums, or photos from favorites or recent activity in the Photos app 
.
Set a screen saver when viewing albums in the Photos app
Open the Photos app
on Apple TV, then navigate to the Shared Albums or Albums category in the menu bar.Note: If you don’t see the Shared Albums category, go to Settings > Users and Accounts > [default user account name], then select Photos and turn on Shared Albums.
Select a shared album from the Shared Albums category or an album from the Albums category, then select Set as Screen Saver and confirm.
Choose whether memories or albums appear in the screen saver
Open Settings
on Apple TV.Go to General > Screen Saver > Type, then select My Photos.
Do any of the following:
Choose to show memories: Select Memories.
Choose to show all photos from favorites or recent activity: Select Albums, then select either Favorites or Activity.
Choose to show only a shared or personal album: Select Albums, then either a shared album in the shared category or a personal album in the albums category.
To adjust other screen saver settings, see Use Apple TV screen savers.