Showing Europe's upset about vote (8)
I believe the answer is:
exposure
'showing' is the definition.
(process of exposing)
'europe's upset about vote' is the wordplay.
'upset' indicates anagramming the letters.
'about' is an insertion indicator.
'vote' becomes 'x' (how votes are marked).
'europes' anagrammed gives 'eposure'.
'eposure' enclosing 'x' is 'EXPOSURE'.
(Other definitions for exposure that I've seen before include "Disclosure - made by a photographer?" , "public attention" , "could cause one's death" , "Unveiling" , "Unmasking" .)