I noticed that when using the mobile view (either on mobile device or from desktop computer) some avatars are broken, including my own, when inside question page. For example:
Quick check show that Emmett's profile picture is taken from gravatar while my picture is hosted on imgur.
Going directly to the broken image URL gave this address:
http://i.stack.imgur.com/rH58B.png?s=30&g=1 and as you can see (until fixed) this bring the following error page:
Imgur is used to share photos with social networks and online communities, and has the funniest pictures from all over the Internet.
Imgur ♥'s Stack Exchange
This is a commercial Imgur installation for the Stack Exchange network. If you'd like your own setup similar to Stack Exchange's then feel free to contact Alan at email@example.com. Otherwise, you're probably not supposed to be on this page...
Changing the "?s=30" to "?s=32" in the URL fix the problem.
Gravatar does not have such white list of allowed thumbnail size thus not affected.
Can this please be fixed by either changing the thumbnail size in mobile view to 32 as well, or adding "30" to imgur white list?