I don't know but it sort of sounds like she might be thinking, trying to work out what you're saying or working out how she should respond. Has she ever done it before?
My T sometimes closes his legs and turns them to one side when I say something that makes him uncomfortable (it's so obvious!) And when I say something really emotional or deep he looks at me with real intensity like he is almost completely submerged in what I'm saying (if that makes sense). Sometimes I wonder if I'm projecting that emotion on him, but he does look at me with an absorbed and almost emotional expression.