See:
The broken image links to:
https://stackexchange.com/users/flair/218674.png which redirects you to https://stackexchange.com/error?aspxerrorpath=/users/flair/218674.png
Here is the header information:
and a curl request:
Nathans-iMac:~ nathan$ curl https://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$
Update
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.
/error?aspxerrorpath=
entry there points to a temporary failure. Try a force reload / cache clear.stackexchange.com
is69.59.197.21
according to my DNS. Perhaps yours is different and we are looking at different servers?wget http://stackexchange.com/users/flair/218674.png
as well, works too. Ah, but on my home server this fails! Suddenly, the customer network here is suspicious...