The Live Photos feature of recent iPhones is a lot of fun. It captures 1.5 seconds of movement surrounding a 12-megapixel still image (think the “moving newspaper" photos in the Harry Potter films). If you want to play the video portion of a Live Photo in macOS Sierra, here’s how:
- Open the Photos app.
- Open any album where a Live Photo is contained
- Open any Live Photo by double-clicking on it.
- Hover the mouse cursor over the Live Photo to play the video portion of the picture in Photos on Mac.
A Live Photo is signified by the little concentric circle and “Live” text in the corner of the picture.
(This how-to is based on my experiences and info on Apple's support pages — where the images sometimes come from.)