The two photos above have the same light source, same light location and same white background. The only difference in the second photo is that the light has been aimed differently. Pointing your light away from your subject (i.e., using the edge of the beam) is a quick way to sculpt much more interesting light for a head shot or portrait.
But how far away do you need to aim it? Further than you'd think. And finding the nice edge to your light is definitely a game of inches.