The image in question -- of workers who drive engines and fit machine parts together -- conveys the sense that the common People are really the "drivers" of the industrial enterprise and the force that keeps its unity together, i.e., the true leaders despite their exploited state. The idea that Giorgio has the secret that can liberate labor into its deserved leadership status is what prompts Nostromo to seek out, as the next paragraph puts it, the "advice of his sagacity."