Screen poser (6)
I believe the answer is:
riddle
I believe this is a double definition.
'screen' is the first definition.
(I've seen this before)
'poser' is the second definition.
(thesaurus)
(Other definitions for riddle that I've seen before include "Perforate with gunshot - poser" , "The large sieve is a puzzle" , "Puzzle or strainer" , "Screen" , "Puzzling question - sieve" .)