I think Aryas character on screen works best when she is allowed to play off someone else. Since season 1 she has always had a 'companion' or someone to bounce off - Sansa, Syrio, Gendry, Hotpie, Tywin, The Hound etc. So far this season she has largely been on her own with very little dialogue so its a complete contrast to what we are used to.
Just my thoughts