Flavour of the Month, having nailed business image (4)
I believe the answer is:
icon
'image' is the definition.
('icon' can be a synonym of 'image')
'flavour of the month having nailed business' is the wordplay.
'flavour of the month' becomes 'in' (I can't justify this - if you can you should believe this answer much more).
'having nailed' is an insertion indicator.
'business' becomes 'co'.
'in' going around 'co' is 'ICON'.
Can you help me to learn more?
(Other definitions for icon that I've seen before include "Superstar" , "Someone uncritically admired" , "Religious painting or symbol on computer screen" , "Religious painting in Greek Orthodox Church" , "Something on computer screen" .)