If I had to guess: "You are a machine." It's reminiscent of Victorian authors describing the heart as pistons or the brain as strings being pulled. Less of a fact and more of a metaphor, a poetic interpretation.

Then, add on the entirely subjective experience each of us has of consciousness: it's not obvious that subjectivity is created or come from machines. Each of us has one good example, and the rest is intuition, induction. At best, "You can build machines like us, because we ourselves are the proof," is a wishful project, rather than a proof.