Scroll to individual photos in the memory: Press the Right Arrow or Left Arrow key, or swipe left or right on the trackpad. You can also swipe the filmstrip to scroll quickly forwards or back.
Display the memory photos in a grid: Click the Memory Grid button in the toolbar.
The new memory appears among your favourite memories in Memories. If you want the memory to appear with your other memories, click the Add to Favourites button Browse your photos in Photos on Mac