When using my Windows Phone 8 there are a number of images that do not do display correctly.
These have never displayed correctly ever since I got it, I've cleared my browser cache as well as hard reseting my phone - not just to resolve this issue :).
From the pop-up menu:
From the user page:
EDIT: This appears to a problem getting the image from the CDN. For example, http://cdn.sstatic.net/outdoors/img/favicon.ico loads fine on a WP 7 device, but not on Windows Phone 8.