Picture within another (5)
I believe the answer is:
inset
'picture within another' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for inset that I've seen before include "Minor figure" , "Training during term time for teachers in state schools" , "Something put into something else" , "Stein (anag)" , "Put (one thing) into (another)" .)