From the Painting Guide: Unless you have a specific reason to add a nymph, in other words it would add to the story or message of the painting, it seems a somewhat artificial thing to do. I would rather develop the emotion of the landscape through nature itself: the sky at the moment is relatively undeveloped and the landscape static. Variations to the sky could change the overall mood of the painting. For example threatening storm clouds, sunlight breaking through clouds, or choosing a time of day when the sky changes colour (sunset, sunrise). Or simply a greater contrast between the white clouds and blue sky. The trees themselves could provide a more unique focus, perhaps by concentrating on a single tree nearer the foreground giving a sense of its age or beauty, or the cycle of its life and its interaction with its environment. A single bird in the sky might look artificial whereas a v-shaped flock of birds migrating would add to the feeling of seasonal change.