A strong contrast between light and shadow creates drama. It captures our imagination because it draws our attention in a unique way. Renaissance artists were notable for this technique. Think "Girl with a Pearl Earring." 

This man interpreted as an 18th-century tailor is not only framed by the window but also by the strong contrast of shadow behind him. There's an aura of mystery. We want to gain a closer look at what he's doing.

What gain do you make in your photo by combining light and shadow?