Growth and decline are fundamentals of nature. Emptiness is ever filled, and ever emptied.
Sound designs that would express the phenomena of environmental changes and movements among various settings, when compared to musical compositions in standard forms, are of an altogether different order.
The former are fabricated in ways that suggest the manner in which a listener might perceive sounds in various times and places in the absence of rhythm, percussion, melody, and so forth.
To call these forms "sketch" or "transformation ambient" for convenience is to distinguish them as being removed from musical forms or moving in non-musical directions, albeit to aesthetically pleasurable ends and for the creative purposes of the listener, whether those purposes are to be immersed in the music, in thought, or in activity such as reading, writing, painting, or conversation.
Still, quiet waters may capture both sun and moon.