In TV, say, you only get a small picture (5)
I believe the answer is:
inset
'a small picture' is the definition.
(I've seen this before)
'in tv say' is the wordplay.
'tv say' becomes 'set' (tv is a kind of set).
'in'+'set'='INSET'
'you only get' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for inset that I've seen before include "Small picture within a large one" , "Small map within larger; teacher training day" , "one image within another" , "Page within a page" , "Small picture within borders of another" .)