Artistic work in someone else's style (8)
I believe the answer is:
pastiche
'artistic work in someone else's style' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for pastiche that I've seen before include "Imitative artwork" , "Norse thunder god" , "Smorgasbord" , "Composition drawn from various sources - maybe it's cheap" , "Imitation of another art style" .)