Final answer:
The subject matter of this painting is landscape, including trees, mountains, and the sky. The content explores the composition, use of light and color, and the relationship between nature and humanity.
Step-by-step explanation:
The subject matter in this painting is landscape, specifically trees, mountains, and the sky. The content of the painting includes the composition, the use of light and color, and the portrayal of the relationship between nature and humanity. The artist's intention may have been to depict the beauty and grandeur of the natural world.