Can all Aztec paintings be clified as codices?

I have to do an art project on Aztec culture, religion, and sacrifical rituals for my spanish cl. I am painting a picture of a snake to represent the god Quetzalcoatl and a human sacrifice. I am wondering if it is correct for me to call the picture of the sacrifice a codice, or is it just a picture? Everywhere I look says codices are scripts, mostly consisting of pictures, so Im pretty confused. Can I call the darn picture a codice or not?