Picture within another (5)
I believe the answer is:
inset
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">picture within another</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(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)" .)