The ability to playback Live Photos in Photos.app is a nuisance at best. So far I've only been able to play them by hovering over them with my mouse, either over the 'Live' tag in the bottom left hand side of a full view photo, or hovering over the photo in the gallery view (which plays without sound).
Is there a keyboard shortcut that can be used to start the preview in one or both views?
Spacebar doesn't work, as that switches between full size/edit mode, and gallery mode. There is no shortcut that I've found in the app's menus.