Yep, I looked at one of the webshot links you provided "the horse!" and you can tell by the panel beside it that it is the bottom row, middle frame. Good catch! You get a brownie point for solving the mystery.
The problem is that the people seeing "horses" and "elephants" in this imagery really don't understand Mayan imagery to begin with. It had its own unique style. I'm certainly not an expert, either, but at least I understand the impact of their stylized god images on their overall art. For example, the elongated "elephant" nose:
Chaak is the Yucatec Maya word for "thunder," a fitting name for the god of rain. The large temple mask at left is from Kabah, a city from the Puuc region of northwest Yucatán. Its curled nose is an exaggerated form of the pointed nose that usually characterizes Chaak; the nose is said to scratch the clouds to bring the rain, or its downward-pointing nose could represent the shape of a whirlwind itself. A pair of fangs at the mouth corners that identify Chaak also appear in this mask. In modern Maya folklore, the rain god often keeps his waters in jars that he releases to pour the necessary rains. The Mayapán effigy censer at right is another outstanding representation of Maya polychrome ceramic. The sculpture may represent either a priest, clad in the garments symbolizing the Rain God Chaak, or Chaak himself. NMAH
http://members.aol.com/hmupuni/deity.htm
I've said it before, I'll say it again - the biggest problem with Book of Mormon apologetics is that the target audience simply does not have adequate background knowledge to judge these claims, and those apologists who do and know better, often remain silent. I will give Brant kudos for rejecting the Done photo as a horse (as Sorenson did before him).