Pretentiously artistic (4)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pretentiously artistic</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for arty that I've seen before include "Trendily into painting" , "aspiring to be creative?" , "Like an aesthete" , "Affectedly unconventional" , "Bohemian" .)