Here you go - from the BBC website
"The programme is live but in the background, Big Ben is clearly visible showing the time nine o'clock throughout. What is the explanation?
We put the programme out live, each Sunday morning, from the BBC studios in West London.
The Andrew Marr show uses the same studio as "Newsnight", "Working Lunch", "The Politics Show", "Newsround" and various other programmes.
The backdrop to the studio is a series of large screens - in effect a video wall. Each programme drops into this video wall whatever image it wants.
The Andrew Marr show uses an image of central London, looking up the Thames and including the Commons, the Eye... and in the distance the City. The aim is to provide a striking scene behind the guests, and since the show has at its heart Westminster politics, it is appropriate.
It is not technically possible to fill this wide space with a single image from a single camera. The backdrop is created by stitching together a series of different camera shots, taken from the top of an office block near the Tate.
They were taken in the summer when the trees were out and in fact there is much more greenery on the video wall each week than can now be seen on the ground. If it were possible to offer a "live" shot that showed the state of the weather, the foliage on the trees�and the time on Big Ben as it is at that moment, it would be preferable. Sadly, that is not technically possible. "
So not a "live" view afterall, but at least it tells you where the video shots are taken from. Here's to more peaceful Sunday breakfasts. (The show is must for us as well!)