How to View Live Photos on an iPhone
Tap and hold the screen on a photo with a three-circle icon in the top left corner.
Open your iPhone's Camera. It's the picture of a camera with a grey background. Tap the dial at the top of the screen. It should turn yellow. Doing this will enable Live photos for the next photos you take. If the dial is already yellow, Live photos are enabled. Tap the white circle at the bottom of the screen. Doing so will take a picture of whatever your camera is facing. Tap the camera roll thumbnail. It's in the bottom left corner of the camera screen. Press down on your Live photo. It should be the first photo that opens. Your photo will animate, displaying a several-second long series of frames that occurred before and after the displayed photo was taken. For example, a picture of your face might show you blinking a few times. 
Open your iPhone's Camera. Tap the dial at the top of the screen. Tap the white circle at the bottom of the screen. Tap the camera roll thumbnail. Press down on your Live photo. 