Still choose not to finish (3)
I believe the answer is:
pic
'still' is the definition.
'choose not to finish' is the wordplay.
'choose' becomes 'pick' (picking is a kind of choosing).
'not to finish' means to remove the last letter.
'pick' with its final letter taken off is 'PIC'.
(Other definitions for pic that I've seen before include "Photo (informal)" , "Photo (colloq.)" , "Image (abbr)" , "film" , "Snapshot" .)