symbolic representation (i.e. a symbol, number, or letter) color or texture to indicate importance placement within the photo to indicate importance or emphasis contrast to other elements in the photo size to indicate level of importance
value which has symbolic representation (i.e. a symbol, number, or letter) value which has color or texture to indicate importance value which has placement within the photo to indicate importance or emphasis value which has contrast to other elements in the photo value which has size to indicate level of importance