The trees were waving their branches, shaking off the dead needles from the winter, and generally looking cheerful. It was as though they were a group of friends all huddled in a group, waving excitedly at me. I couldn't take my eyes off them for several moments, as they looked so exuberent in the sunshine.
Later on I looked out the window again, and they had all settled down. So I figure that earlier they were just happy to see me and waving good morning.