Upset about rivals displaying fine artworks (5)
I believe the answer is:
virtu
'fine artworks' is the definition.
(virtu can mean art objects)
'upset about rivals displaying' is the wordplay.
'upset' is a reversal indicator.
'displaying' indicates the answer is hidden within the clue.
'utriv' is hidden in the letters of 'about rivals'.
'utriv' backwards is 'VIRTU'.
(Other definitions for virtu that I've seen before include "Love of the fine arts" , "Knowledge of fine arts" , "Curios" , "Love for fine art" , "Objects of art" .)