Sorry, I was trying to copy and paste the title and clicked answered. I appear to lack the permissions to change it back.
I'm poking around internally to try and get you some official documentation. The explanation is mundane, but I want to make sure that it's 100% accurate.
In the meantime, rather than asking you to take my word, I'd encourage you to just take a look for yourself. We're explicitly very transparent about what we're doing, and the requests are readily inspectable. For HTTPS requests, you can use a web debugging proxy to see what's going across in cleartext.
For this request in particular, you can literally just type the address into a browser:
http://geo2.adobe.com/
For convenience, this is what's coming back for me:
http://geo2.adobe.com/
Country: "US" Accept-Language: "en-US,en;q=0.9"
In contrast, if you're not familiar with what your browser normally sends for each request, you might find the fingerprinting section here enlightening: https://panopticlick.eff.org/
Hope that helps!