Edit to explain my somewhat rushed post above.
The link is to an Evening Standard report about missing Sarah. There is an 11-second video with the caption "Clapham Common appeal CCTV" below it. There seems to be no other reference to the video in the article. My gut feeling is that the Standard have included this video in their report by mistake, and will soon delete it.
As I write, I see others are now weighing in with the same concerns and views that I had when I first saw it, so I will not add any more to this post. Congratulations to
arrogantcat for saving it - something I couldn't work out how to do - and to others for so quickly explaining it.