You can now edit your Live Photos in iOS 11. The feature, which captures a short video clip when you take a photo, was added in iOS 10, but with limited editing functionality.
You can ensure Live Photos are switched on by tapping the concentric circles icon at the top of the screen when Camera is open.
To edit a Live Photo, take a picture, or find one you’ve previously taken, and tap Edit. On this screen you’re presented with the timeline of the clip. Tapping a different part of the timeline will enable you to change the main or “Key” photo that you see in your Camera Roll.
You can trim the video by moving in the arrows on each end of the timeline. You can also add filters and crop the image in the same way as any other photo.