Posed for a portrait (3)
I believe the answer is:
sat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">posed for a portrait</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for sat that I've seen before include "Used a chair" , "Was in session" , "part of the weekend" , "twenty-four hours" , "Took (examination)" .)