"The upper front facade of the West Building was originally decorated with a spectacular entablature running between stacked corner masks. Unfortunately, most of this entablature fell before the era of modern photography, so that only two small sections were photographed in situ at the end of the last century.
The best information about the reconstruction comes from the two short sections of entablature that never collapsed. These included a short section between doors 2 and 3, and a longer section over door 6 and 7." [next photo].
However, Schele & Mathews do believe the reconstruction of the facade is essentially correct.
Schele & Mathews, The Code of Kings, p. 276-7
The intact section over doors 6 and 7 which never collapsed.
Two entwined serpents run the whole length of the entablature. The lower serpent has a diamondback pattern, while the upper serpent on the SE corner has a feathered body.
A lord holding a scepter survives on the southern side of the frieze.
West Building detail.
Stacks of three uncollapsed masks rise over door 6.
"The masks have headbands with multiple flowers mounted over feathers that once again mark these creatures as Itzam-Ye birds. The earflare assemblages are also flowers, and the frames on both sides of the masks consists of serpent heads with feather fans and protruding bifurcated tongues. They are shown in profile view and are stacked four high [although the highest serpernt is very small and hard to discern]."
Shele & Mathews, The Code of Kings, p. 279
A Maya thatched-roof house with a mask on top is the sign that this building is Itzam Nah, a "conjuring house."
Further to the left, we see the tail and rattle of one snake and the rearing head of the other snake as it emerges from behind the mask stack. A human head emerges from the jaws of the snake. The serpent's head once again has a feather fan above its head marking it as a war serpent.
Schele & Mathews, p. 283
"The designs were strange and incomprehensible, very elaborate, sometimes grotesque, but often simple, tasteful, and beautiful. Among the intelligible subjects are squares and diamonds, with bursts of human beings, heads of leopards, and compositions of leaves and flowers, and the ornaments known everywhere as grecques. The ornaments, which succeed each other, are all different; the whole form an extraordinary mass of richness and complexity, and the effect is both grand and curious.
And the construction of these ornaments is not less peculiar and striking than the general effect. There were no tablets or single stones representing separately and by itself an entire subject; but every ornament or combination is made up of separate stones. Each stone, by itself, was an unmeaning fractional part; but, placed by the side of others, helped to make a whole. Perhaps it may be called a species of sculptured mosaic."
John L. Stephens, Incidents of Travel in Central America, Chiapas & Yucatan, Vol. 2, p. 422