Art style is shown in field (7)
I believe the answer is:
realism
'art style' is the definition.
'realism' can be an answer for 'style' (thesaurus). I am not certain of the 'art' bit.
'is shown in field' is the wordplay.
'shown in' is an insertion indicator.
'field' becomes 'realm' (synonyms).
'is' inserted inside 'realm' is 'REALISM'.
Can you help me to learn more?
(Other definitions for realism that I've seen before include "Acceptance of life as it is" , "Rationality" , "Pragmatic approach to the facts" , "True-to-life quality" , "Practical approach" .)