Envisage getting in just before the end of picture (7)
I believe the answer is:
imagine
'picture' is the definition.
(picture can mean to visualise or imagine)
'envisage getting in' is the wordplay.
'envisage' becomes 'image' (imaging is a kind of envisaging).
'getting' indicates putting letters inside.
'image' going around 'in' is 'IMAGINE'.
'just before the end of' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for imagine that I've seen before include "Conceive; fancy" , "Believe to be so, suppose" , "Classic Lennon song" , "Picture to oneself" , "Fancy - dream" .)