I wanted to have some cool movement in the background that would add to the image of this model without distracting the viewer. The background is a photo I took at a completely different time and put it in post. If you notice the tones both on the model and in the background totally work together as well as the position of the lights equal to the position of her face gives off a good eye-line so the viewer is guided to look first at the model then at the swoosh of lights. Having a good eye-line is important.