As in a mirror, so (Brahman may be seen clearly) here in this body; as in a dream, in the world of the Fathers; as in the water, he is seen about in the world of the Gandharvas; as in light and shade in the world of Brahmâ.

In plain words: In this human life, Brahman can be seen clearly, like a face in a mirror. In other worlds it is seen less clearly: blurry like a dream in the world of the ancestors, shaky like a reflection in water in the world of heavenly singers, and only in the world of Brahma (the creator god) as clear as light is from shade.