When the Primeval Elves were meticulously filmed by the camera, it signified that their information had been recorded in the "photographic realm."
Among the gods, the God of Light and Shadow represented the quite broad concept of "light and shadow." His appearance manifested as an undefined silhouette person, whose form was sometimes intricate, sometimes crude, and occasionally looked like the random foot soldier shadow demons summoned by mages in a botched spell.
However, what the Sixth Era dreaded most was the act of assessing the strength of a life form based on appearance, extending even beyond life forms. The motionless stone by the roadside or the dead skeleton lying down could very well be stronger than you, and their stillness stemmed merely from pure indolence.