Reply #1

You fail to account for the fact that the alien intelligence monitoring us does not want us to know of their existence.

They had not anticipated we would find the face on Mars. Accordingly, when they found we had discovered it, they altered it beyond recognition.

That's why it doesn't show up in the later picture.

Of course, you dismiss this readily explainable event, and ignore the mounting evidence of other structures, statutes, and apparent underground civilization that has accumulated since that time.