One magazine starts to employ sexy pictures (6)
I believe the answer is:
images
'pictures' is the definition.
('image' can be a synonym of 'picture')
'one magazine starts to employ sexy' is the wordplay.
'one' becomes 'i' (Roman numeral).
'magazine' becomes 'mag' (abbreviation for magazine).
'starts to' says to take the initial letters.
The initial letters of 'employ sexy' is 'es'.
'i'+'mag'+'es'='IMAGES'
(Other definitions for images that I've seen before include "Semblances" , "Mental representations or figures" , "Reflections in mirrors" , "works by Debussy" , "Likenesses or effigies" .)