It's a nice colored pencil/ shading/ teaching value lesson. Medium blue construction paper is used for background, and color is added with a darker shade of blue for the shadow side and white for the lit side. Students can choose any colors for accessories and snowflakes can be added in the sky.
Another great idea for teaching value using shades and tints. The original poster of this project, art teacher Jessica Young, gives a great explanation of the steps and tips she used with her fourth-grade students.
Geometry Fun through the arts! I have a geometry unit coming up for my 5th graders. I think I will use this idea but include some parameters for my kids. For example, I could require the shapes in the center to be twice the size of the same shapes on the outside - as if looking through a magnifying glass - just to add some more math!