hooberus,
You are confusing the aspects of raw exploratory research, the testing of theories against found facts, and the education of the young.
The "Face on Mars Photo", if it is to be used as a teaching tool in schools, might be used in a Political and Social studies class to evaluate the public's documented response to what has amounted to be an urban legend, and how it lingers after having been proven to be shadows.
It has no place in a science classroom other than as a particularly normal and uninteresting geologic feature of the planet Mars, as that is what the scientific observation has proved it to be. It is option #1: "A purely naturalistic object."
To present it as anything else in a science classroom for our youth is to mislead them about facts.
Similarly, teaching and discussion of flat-earthism belongs in a History classroom.
Similarly, teaching and discussion of a creator belongs in a Comparative Religions classroom.
Eric