This is what you can do when your images don’t show up in WordPress on your iPhone, iPod or iPad:
If you save you JPG as a progressive JPG with scans (ie 3 scans) iPhone, iPods and iPads won’t be able to render the image on your WordPress site.
There is an easy way to fix this though. You can resave your JPG as a baseline optimized JPG. After doing this everything should work properly and you will be able to see your JPG photos again.
This is the original progressively scanned JPG image. It had 3 scans and was saved with a quality setting of 11.
This is a sample of the JPG after resaving it as a baseline optimized image for Iphones, iPods and iPads to use on WordPress sites.