Picture that is in magazine? The opposite! (5)
I believe the answer is:
image
'picture' is the definition.
(I know that picture can be written as image)
'that is in magazine? the opposite' is the wordplay.
I cannot quite understand how this works, but
'magazine?' could be 'mag' (abbreviation for magazine) and 'mag' is present in the answer.
'that is' could be 'ie' (abbreviation for id est, 'that is' in Latin) and 'ie' is found within the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for image that I've seen before include "Optical counterpart in mirror" , "Representation, picture" , "Likeness U symbol" , "Picture (involving one letter change from 10)" , "Epitome" .)