News multiscreen query

Just intrigued really...
When I exit BBC News Multiscreen where we get the bewildering choice of two
"streams" (sorry, don't know the technical term !), for a fraction of a
second, there is a third stream showing on the right hand of the screen
showing BBC Parliament (I think !). Why is that and is the number of
"streams" restricted due to limitations of the digital terrestrial system
or just a choice from the broadcaster ?

Nildram news wrote:

Just intrigued really...
When I exit BBC News Multiscreen where we get the bewildering choice of two
"streams" (sorry, don't know the technical term !), for a fraction of a
second, there is a third stream showing on the right hand of the screen
showing BBC Parliament (I think !). Why is that and is the number of
"streams" restricted due to limitations of the digital terrestrial system
or just a choice from the broadcaster ?

Roughly speaking the two news streams and Parliament are broadcast in
the same space as one whole screen programme. The bit you don't want
is then masked out with a MHEG layer. As you exit this is turned off
momentarily before you actually change to the new programme so you see
it all as broadcast.

Parliament is shortly to go full screen and there is talk of this
being acieved by ditching the news streams. Perhaps the BBC have found
out that nobody watches them - I never do.
--
Phil Cook looking north over the park to the "Westminster Gasworks"