HEIF files ‘appear’ to be the same thing, but at this stage I can’t clearly find information explaining if there’s a difference, and if so what that is. If I find out more I’ll update this post.
I expect something else has changed recently, as I’m seeing the files turn up over email from other parties where I’d never seen them before. Early on the files were being converted back to JPEG in many situations, including OneDrive Photo Roll syncs. The format was added in iOS11 and created when doing things like taking a photo. Created by the Moving Picture Experts Group (MPEG) and adopted by Apple amongst others, it’s looking like a replacement for the old JPEG image format. If you haven’t come across these file formats already, you probably will soon.
