"At present there remains enough of only one of the supernatural face panels to make a judgement about their original form. This one mask is the rightmost of the three on the façade facing the southeast Main Plaza. It contains several features characteristic of Late Preclassic Maya and Olmec art: "flame eyebrows"; a cleft form between the eyebrows; a large, cleft, squared oval forming the lips with a downturned opening between them. The eyes are almond-shaped human eyes encased in larger ovals.
Standard Maya features are the large earspools with oval pendants and two sets of volutes, one above the earspools and one emanating from the upper part of the head. THe stucco frame of the mask is in the form of a Maya supernatural under-eye line, with a series of symmetrically distributed volutes and curvilinear forms below. The face is about 45 cm square, and a deeper, recessed area separates it from the cartouche, adding the illusion of greater depth to the relief."
Carolyn E. Tate, Yaxchilan: The Design of a Maya Ceremonial City, p. 160