Shortly choose film (3)
I believe the answer is:
pic
'film' is the definition.
(abbreviation for picture)
'shortly choose' is the wordplay.
'shortly' means to remove the last letter.
'choose' becomes 'pick' (picking is a kind of choosing).
'pick' with its last letter removed is 'PIC'.
(Other definitions for pic that I've seen before include "Image (abbr)" , "illustration" , "film" , "Photograph (colloq.)" , "Photo (informal)" .)