What is the meaning of the skull at the center of the representation of Coatlicue?

Answer from the V.M. Samael Aun Weor and the magazine.

On her chest hang sagging breasts; a leather necklace, adorned with hearts amidst four outstretched hands, culminates in a skull at the level of the deity's navel and extends up to her shoulders. Her arms are pressed against her body with flexed forearms; below her hands, which end in the heads of precious serpents with half-open jaws and upper incisors like claws, hang smooth, geometrically cubic rectangles with a vertical line in the center of each face, a symbol of the perfection of the works in her hands. On her shoulders and elbows are tiger claws and eagle eyes.

Her short skirt of intertwined snakes, their heads pointing downwards, is cinched at her waist by a wide belt of precious serpents. Knotted beneath her skull, with its full eye sockets and defiant gaze, the heads hang forward like untied ends of a tie, symbolizing that everything in the universe is a product of sexual fire.

The skull at the deity's navel is not the end of her necklace nor the clasp of her skirt belt, but rather Coatlicue, the devourer of men and goddess of the earth and death, whose body projects forward between her thighs, from her lower abdomen to her feet.

Excerpt from the book: Aztec Christic Magic, Monograph No. 10 "Coatlicue".

Answer from the magazine "The The wisdom of the Being.".

Her skirt of intertwined serpents, a symbol of marriage and partnership for sacred duties, reminds us of the sexual decency that single and married people should practice in order to bring about the death of all their defective selves. This death is symbolized by the human skull on her solar plexus, from which two downward-facing serpents hang, symbolizing that everything in the universe is a product of sexual fire. Furthermore, this skull at the deity's navel is not the end of her necklace nor the clasp of her skirt belt, but rather Coatlicue, the devourer of men and goddess of the earth and death, whose thick serpent body projects forward between her thighs, from her lower abdomen to her feet. She swallows men who no longer possess selves and guides them to become feathered serpents, Quetzalcoatl. She rejoices when we kill the ego; psychological aggregates must be eliminated from our psyche, consciously or against our will. She is the one who kills defects. He who does not know the laws of the Mother will never reach the Father.

The Magazine "The Wisdom of Being" 107: "Coatlicue."