Imagines they'll show old-fashioned films? (8)
I believe the answer is:
pictures
'imagines' is the definition.
(picturing is a kind of imagining)
'show old-fashioned films?' is the wordplay.
'show' becomes 'picture show' (synonyms).
'old-fashioned films?' becomes 's' (I can't justify this - if you can you should give a lot more credence to this answer).
'picture'+'s'='PICTURES'
'they'll' is the link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pictures that I've seen before include "Paintings" , "Visual representations" .)