Because of the nature of this shot (testing the lights), there's in fact no posing involved. It depicts the girl with her natural expression. Her eyes are really the eyecatcher here and as one say: "The eyes are the mirror of the soul", in this case in my opinion her eyes reflect the hesitant, the curiosity for what will come (but maybe also a bit nervous) and the confidence.
The direct eyecontact at the beginning of the shoot tells me we are on the same wavelength: you almost can't got untied.
The pose of her shoulders could reflect they way she would handle the tension during the shoot: it would literally slide off her shoulders.
In postprocessing this image, I wanted to have a almost painterly look and feel to it. For this purpose I used a texture for the background.