Likeness that is covering magazine (5)
I believe the answer is:
image
'likeness' is the definition.
(I've seen this before)
'that is covering magazine' is the wordplay.
'that is' becomes 'ie' (abbreviation for id est, 'that is' in Latin).
'covering' is an insertion indicator.
'magazine' becomes 'mag' (abbreviation for magazine).
'ie' placed around 'mag' is 'IMAGE'.
(Other definitions for image that I've seen before include "personality" , "Optical counterpart in mirror" , "Pictorial representation" , "Likeness; metaphor" , "Copy" .)