The Memories screen in the Photos app navigate down to show the Info pane, then do any of the following:
Change the mood: Navigate to Mood, then navigate down and select the mood you prefer.
Change the duration: Navigate to Duration, then navigate down and select Short, Medium, or Long.
Access audio controls: Navigate to Audio, then navigate down and select the option you prefer.
In the Memories category of the Photos app select any of the following:
Add to (or Remove from) Favorite Memories: Add or remove the memory from the Favorite Memories album found in the Albums category of the Photos app.
Delete Memory: Permanently delete the memory on Apple TV and on all devices connected to your iCloud Photos account.
Block Memory: Block memories of that particular day or place on Apple TV and on all devices connected to your iCloud Photos account.