HEIC image thumbnails don't appear on older iPad Wife has an iPad Mini running iOS 9 or so, and an iPhone 7 running iOS 11. Images shot in HEIC get synced to her iPad via Photos app, but no thumbnails appear. If clicked, the images appear normally. Seems iPhone is converting images for sharing via Photos but is not including the thumbnails... anyone else seen this?

(My iPad is running iOS 11 - so I have only seen this on my wife's device - can't tell if it is a flaky device or a bug in image sharing conversion)
I encountered the same issue with a friend's iPad (running 9.3.5) and iPhone 7 (running 11.1.1). Apparently, the iPad Photo app's thumbnailer is unable to handle HEIF files.

I worked around this by going into the iPhone's Settings > Camera > Formats and selecting Most Compatible. Any pictures taken after that show up properly on the iPad.