Contemplation of mirror image (10)
I believe the answer is:
reflection
I believe this clue is a double definition.
'contemplation' is the first definition.
(synonyms)
'mirror image' is the second definition.
(synonyms)
'of' is the link.
(Other definitions for reflection that I've seen before include "mental study's required" , "serious thought?" , "Mirror image" , "Effect of not absorbing light" .)