Al Jazeera publishes fake picture of Libyans celebrating Qaddafi's sons capture

I forgot that I have saved this picture that was published in Al Jazeera on August, 22 in the article "Libya freedom is in the air" by Larbi Sadiki.
Why not a real photography?
Why?

Update November 25, 2011

Now we know why: Saif al-Islam was captured November, 18, 2011.