Soft winter sunlight, from the south, backlit the ladies, leaving their faces largely in shadow. It is a time-honored technique of portrait photography, thought to instill a sense of inner life. Side lighting (not shown) is more common, however, because it can dramatically model the features of the face. The gentleman with the sunglasses is three-quarters lit by light from the windows. In my thinking, natural light, as here, produces portraits of a more natural character.