Meaning by proxy
PLAYBOY: But isn’t television itself a primarily visual medium?
McLUHAN: No, it’s quite the opposite, although the idea that TV is a visual extension is an understandable mistake. Unlike film or photograph, television is primarily an extension of the sense of touch rather than of sight, and it is the tactile sense that demands the greatest interplay of all the senses. The secret of TV’s tactile power is that the video image is one of low intensity or definition and thus, unlike either photograph or film, offers no detailed information about specific objects but instead involves the active participation of the viewer.