The concepts of atmosphere or mood are commonly used in aesthetics to describe an immediate immersive experience of an environment. We contrast this idea with the tradition that characterizes the experience of mood, atmosphere, or aura as involving distance (Riegl, Benjamin, Adorno).
According to this tradition, art borrows its effect from the experience of a 'distanced nearness' one may encounter vis a vis certain natural phenomena. We interpret this tradition as allowing us to approach the exhibiting of artefacts as profoundly aesthetic, regardless whether what is to be exhibited is art, archaeological findings, or, for example, fossils.
What museums of art have in common with museums of natural history is they are artificial preserves of the sense of distance not unlike that experienced on rare occasions in natural environments.