I always saw your (relatively) new flair, but also see that Web-Sniffer is giving different results. I don't think there's any CDN involved, as I think the CDN uses specific domains, like cdn.sstatic.net. And both my own computer and Web-Sniffer connect to 64.34.119.12.
So I guess there's some load balancer in the SE server farm, and that each server has its own cache? Flair is known to be cached on the server for quite some time (and the server always tells the browser to cache for 86,400 seconds, being 1 day). Then the flair from the server to which the load balancer keeps sending you, simply was generated before Imgur and I happened to be sent to another server. And then the caches on the different servers also have different expiration dates.
More details:
Yesterday, for me, showing the same flair that you uploaded to Imgur:
Content-Length: 7313
Last-Modified: Wed, 16 May 2012 18:49:02 GMT
I seem to get the same results when logged in, and when using some private browsing mode, and also when using a different internet connection (different IP address). I am on IPv6, but the connection to Stack Exchange is using IPv4.
For Web-Sniffer, yesterday:
Content-Length: 6862
Last-Modified: Wed, 16 May 2012 17:07:41 GMT
That Web-Sniffer result is the same as someone reported in a comment, seeing the old flair.
Today, I see you now have 8 silver and 45 bronze badges, and the Meta logo, and get:
Content-Length: 7648
Last-Modified: Thu, 17 May 2012 09:58:59 GMT
Web-Sniffer now reports:
Content-Length: 7635
Last-Modified: Thu, 17 May 2012 10:01:29 GMT
For yesterday, Imgur gets me yet other data. I guess there the Last-Modified is just the upload date, so should be ignored. And as for Content-Length, they might even re-render the image too? If they are not re-rendering (today they have the same length as Web-Sniffer does) then there were at least 3 different image sizes yesterday, which could indicate at least 3 servers then? For your yesterday's image:
Content-Length: 7287
Last-Modified: Wed, 16 May 2012 18:44:34 GMT
Today, just making Imgur copy from http://stackexchange.com/users/flair/205662.pnghttps://stackexchange.com/users/flair/205662.png again, I get the same Content-Length as Web-Sniffer:
Content-Length: 7635
Last-Modified: Thu, 17 May 2012 10:36:51 GMT
That copy also shows the new badges and the Meta logo, but given the Web-Sniffer headers, it was still generated a bit later. And with a slightly different size?
