Offering the proposition "Media is the messages, " Murshall McLuhan indicated that the modality of media consumption can define our kinetic sense and thoughts. The unfortunate acceptance of McLuhan's arguments invited the lack of the sociological scrutiny. This paper will rethink the theoretical implication of McLuhan's proposition from the viewpoints of social system theory developed by Niklas Luhmann. His theory clarifies the theoretical difference between face-to-face communication and mediated communication, and the concept of "observation" will give us the alternative idea of "Medialiteracy".