... in film (therefore, like an artist) (7)
I believe the answer is:
picasso
'an artist' is the definition.
(Picasso is an example)
'in film therefore like' is the wordplay.
'in' indicates putting letters inside.
'film' becomes 'pic' (I've seen this in other clues).
'therefore' becomes 'so'.
'like' becomes 'as'.
'pic'+'so'='picso'
'picso' placed around 'as' is 'PICASSO'.
(Other definitions for picasso that I've seen before include "pioneer of Cubism" , "Spanish painter, d. 1973" , "Pablo ,,,,,,,, great late Spanish artist" , "famous artist" , "Prominent cubist" .)