I am taking a long time to get the picture (5)
I believe the answer is:
image
'the picture' is the definition.
('image' can be a synonym of 'picture')
'i am taking a long time' is the wordplay.
'i am' becomes 'I'm' (contraction).
'taking' means one lot of letters go next to another.
'a long time' becomes 'age' (an age is a period of time).
'im'+'age'='IMAGE'
'to get' acts as a link.
(Other definitions for image that I've seen before include "Picture (involving one letter change from 10)" , "Visible impression" , "Likeness of person or thing" , "Purplish pigment; pool" , "Public impression" .)