I think that one of Zeus' most human qualities that is evident in the Prometheus myth is his sense of anger and wrath at Prometheus. Zeus is shown to be filled with rage at the idea that fire was given to human beings. He is also shown to be one consumed with anger that the prospect that humans would be taught how to cheat the gods. Zeus is not the impartial force of the divine. He's angry. He's vengeful. Along these lines, the brutality and repetitive nature of the punishment that he exerts on Prometheus is a human representation of how justice and vengeance are often closely linked. Zeus is not one who rises above human anger. Rather, he embodies it. Zeus is angry and his punishment of Prometheus shows this. He is one who does not take kindly to being taken "for a ride." Finally, Zeus shows himself to be susceptible to being flattered and complimented. Zeus' initial acceptance of human offerings as what he perceives to be the good meat as opposed to the uncooked meat is a symbol of how Zeus wishes to have his ego stroked and patted. Zeus' own willingness to have his ego appeased is an example of how his own human traits are on display in the myth.