The light coming from the corner creates shadows on the both the wall and the floor. The light is also reflecting off of the other walls in the room, partially lighting the shadows so texture is still visible.

The sunlight behind the photographer outlines him in shadow across the flowers. The flowers are almost too bright to see anywhere but in the shadow.

There is strong key light in this picture, and no fill light at all, making the shadows sharp and dark. The crookedness of the shadows doubles the effect of the crooked nails.

The man is standing in front of what appears to be a projector. There is obviously only the one source of light in the picture, giving him a sharp dark shadow.

The key light shines across the keyboard, creating a plethora of shadows in between the keys, and also right outside its beam. The keyboard itself is rather plain, but the shadows make this picture interesting.