I like the scene but I also get that 'something not right' niggle. I don't think the set is too small, you can see the woman's shadow on a pillar and that gives an idea of the scale. After looking at this for a while I noticed that the background sky gets brighter as you go down- implying the sun is setting/rising, but the shadows imply the sun is behind us. Maybe, subconciously, that's what was bugging me.