The first word "Beware" is separated by an ocular eye petroglyph. Do not examine this eye! It is a thought catcher and direct viewing of any open eye is forbidden. Perhaps this is due to the culture on which this society was based, direct eye contact was considered rude and disrespectful. This includes any open eye in the temple, either inscribed or living.
Crosseye Freeviewing stereography requires no equipment like special glasses. It meerly requires one to be able to flip the switch in their head, and be able to place the left eye on the right image and the right eye on the left. If you get it, then you will enjoy them. Else if you don't get it, then just enjoy the pictures individually, and keep your intelligence test results to yourself.