Panorama is understood to be broadcast (5)
I believe the answer is:
scene
'panorama' is the definition.
(I know that panorama can be written as scene)
'understood to be broadcast' is the wordplay.
'understood' becomes 'seen' (I've seen this before).
'to be broadcast' shows a homophone (sound like) (I've seen 'being broadcast' mean this).
'seen' is a homophone of 'SCENE'.
'is' acts as a link.
(Other definitions for scene that I've seen before include "Where things happen" , "Subdivision of act in play" , "Landscape; public display of anger" , "site" , "Drama; setting" .)