I have this image : "http://interstatic01.gameloft.com/igp/videos/images/d9/end_screen_71.jpg" In this very simple html, it doesn't display for the 2 devices mentioned in the title.
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div ><!-- it may show full image depending on browsers, eg: firefox -->
<img src="https://i.sstatic.net/nXxT5.jpg" />
</div>
</body>
</html>
Note: if i enter the url directly in the url bar of the safari browser, i can see it. It just happens when it is in a tag or when set as css background
The image is simply too large for these devices (see the Know iOS Resource Limits section). You need to serve a smaller image for these devices (how this is done is a different question to which I don't know the answer).
William Malone has a Maximum Image Size Calculator that allows you to enter an image size and it tells you which devices are capable of displaying an image of that size.