The broken image links to:
Here is the header information:
and a curl request:
Nathans-iMac:~ nathan$ curl http://stackexchange.com/users/flair/218674.png <html><head><title>Object moved</title></head><body> <h2>Object moved to <a href="/error?aspxerrorpath=/users/flair/218674.png">here</a>.</h2> </body></html> Nathans-iMac:~ nathan$
Both me and @MartijnPieters have tried from various locations and it seems to be a hit and miss thing. From my location I get redirected, but from my personal VM the image downloads correctly.