Also, it is peculiar that almost nobody in the tape looked at the camera, which is hard to do unless trained to do so like actors are, or such looks were removed by editing.
It is also possible that the tape was made surreptitiously, though the differing camera angles would have to be done by separate cameras. Bin Laden's bulk appears to change in different shots. >From the side he looks heavier than usual, but from the front about the same stringbean. The side shot might have been due to distortion -- it was closer in than the frontal. If the tape is legitmate, I'd say it probably was made to boost the reputation of the Saudi sheik sitting to bin Laden's left. He is the second-most person featured. Could be bin Laden made an appearance and agreed to the tape for promotion of the Sheik's agenda. Perhaps bin Laden was on a tour himself of a batch of sheiks arranged in adjoining rooms, anointing each, maybe even doing a fund-raiser like our photo-addicted pols. Certainly UBL was behaving identically to politicians out working the crowd, bragging, kidding, kissing, pretending to love the audience, acting as though all of it is not for video outreach. True, politicians send in cut-outs and UBL could have sent his double of which he must have several.