Imgur used to block traffic from FreeOnes. [See Connor MacLeod's thread concerning this.] Connor is a moderator here. Many Imgur links, and images did not show up on the FreeOnes board. And sometimes when we copied and pasted the link, we got back 403 forbidden errors. Though sometimes they did work, if we opened them up in a separate tab in Chrome or Firefox and then did the copy/paste.
What Adam is saying is that it is still private. In reality, it is truly a privacy issue. Your girlfriend wants you to see her pictures. But does she want the entire world? If she's a pornstar in the public eye then probably yes. But you should get her consent first.
What compounds the issue is that Imgur also implemented restrictions on adult content over there about eleven months ago. You have to be a verified account owner in order to post images of an adult nature, that includes all forms of nudity. The same holds true for trying to view images of adult content. Meaning that you have to be age 18+ or 21+ in certain jurisdictions in order to post it and then conversely to see it. Most of us don't have accounts there, so that is the reason why we are being blocked. Not really blocked, in the true meaning of the word, but the Imgur owners want us to sign in. Therefore, they want us to verify our ages. Thus, we are unable to see her pictures that you put up.