The raw data from the Twitter object is telling me that the link is .jpg
– and since this data is pulled on the server side, I can’t imagine why and how it would render differently on different browsers.
There’s no browser plug-in that could possibly be substituting links?
Alternatively, sometimes mobile networks cache images strangely (or at least they used to). Do you get the same problem when you access the site (on your mobile) via wifi and via mobile?
The only other thing that might be the problem is if the image was recently changed and the old image is being cached. But this would only be happening if @miles_alvinc only had a few tweets or you were using a search widget.