Another example is a face-powder palette in slate. The wavy lines on the body of the fish are not scales, they illustrate waves and symbolize water.

But waves are written vertically in the glyph for water pools:

The fish therefore is swimming upwards. This type of fish keeps its eggs in its mouth and symbolized rebirth - when the small fish were leaving its mouth they were 'reborn'. The Egyptians believed that a dead person in his afterlife would arise from the water like the sun in the east.