Interior design staff reflected about city (5)
I believe the answer is:
decor
'interior design' is the definition.
(I've seen this before)
'staff reflected about city' is the wordplay.
'staff' becomes 'rod' (I've seen this before).
'reflected' is a reversal indicator.
'about' means one lot of letters goes inside another.
'city' becomes 'ec' (the City of London postcode).
'rod' backwards is 'dor'.
'dor' placed around 'ec' is 'DECOR'.
(Other definitions for decor that I've seen before include "Interior design; stage scenery" , "Credo (anag.)" , "Scheme of interior furnishings" , "(Room) design" , "Colour scheme, furnishing etc. of a room" .)