Light is a character

 Light plays a character in this photo because the sun is shining through the clouds, and makes the mountain look like a silhouette.

 In this photo, the lighting at sunset allows for the array of colors in the sky.  The photo is fairly simple, but the lighting in the sky is what makes it intriguing.

Again, the lighting in the sky and clouds allows this photo to demonstrate complementary colors blue and orange, and a very unique texture.