The issue is that the server is configured to only accept traffic coming from Bitcointalk. That doesn't mean it doesn't work on other forums. I just can't guarantee that they always work.
That actually make sense, talkimg images posted in altcoinstalks loads too long, you can observe it when you load a thread with talkimg image on it that the tab is still loading and the lower left/right of the browser has "Transfering data from talkimg.com.." for too long.
But, I ask, do you think this "restriction" should be lifted?
If there's no downside on the server and no legal issue (copyrights)
(well you can mention it on the website terms), why not?