The ipad has more resources (ram/resolution/processor) available than an iphone/ipod so it is able to handle some of the bigger images that these can not.
I’ll try doing a test with the image that fails to see at which point it would be displayed. Unfortunately if I am understanding some of the information I’ve come across there is also issues with pages containing more than 10 megabytes of images. Since we’re allowing 8 megabytes max size and I know some of our pages go over 2 in size on their own it could be hitting this restriction in total size.
I’m surprised by these limits with Safari considering there doesn’t seem to be an issue with other browsers on android phones. (maybe older android phones?)