I'm taking a long time producing pictures (6)
I believe the answer is:
images
'pictures' is the definition.
(I know this)
'i'm taking a long time' is the wordplay.
'taking' means one lot of letters go next to another.
'a long time' becomes 'ages' (ages can mean a very long time).
'im'+'ages'='IMAGES'
'producing' acts as a link.
(Other definitions for images that I've seen before include "Visual counterparts in lens or mirror" , "'Reflections, likenesses (6)'" , "Mental representations or figures" , "Likenesses or mental pictures" , "These doubles could be spitting" .)