Shadow Art

It is also believed as an alternative construct that shadows are in fact a representation of God's presence around an object; like a halo. Early eastern beliefs also play to this theory.
Heraldry
In heraldry, when a charge is supposedly shown in shadow (the appearance is of the charge merely being outlined in a neutral tint rather than being of one or more tinctures different from the field on which it is placed), it is called umbrated. Supposedly only a limited number of specific charges can be so depicted.