Sync your iCloud photos on Apple TV 4K
The first time you open the Photos app 
on Apple TV 4K, you’re prompted to sync all of your iCloud photos, or only your Shared Albums. You can change which photos are shared at any time in Settings.
Go to Settings
on Apple TV 4K.Go to Profiles and Accounts > [default profile], then select Photos.
Select iCloud Photos to turn it on or off.
When you turn it on, you’re prompted to confirm on another Apple device.
Note: Only the default profile on Apple TV 4K can sync their photos and view content in the Photos app. See Change the default profile on Apple TV 4K.
iCloud Photos automatically stores your full-resolution photos and videos in iCloud. iCloud Shared Photo Library lets you share photos and videos seamlessly with up to five other people (separate setup is required on an iPhone, iPad, or Mac). You can access iCloud Photos and Shared Photo Library from any device using the same Apple Account.
You can’t edit photos and videos on Apple TV 4K, but you can use the Photos app on iPhone, iPad, or Mac to edit them and have those changes automatically update on Apple TV 4K and all of your other devices.