Arrived before artist, producer of pictures (6)
I believe the answer is:
camera
'producer of pictures' is the definition.
'arrived before artist' is the wordplay.
'arrived' becomes 'came' (come can mean to appear or arrive).
'before' says to put letters next to each other.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'came'+'ra'='CAMERA'
(Other definitions for camera that I've seen before include "A court held in it is private" , "Snapper's equipment" , "Snapper?" , "In which people privately discuss" , "Item of film and TV equipment" .)