The episode title refers to a famous quotation from mass-media analyst Marshall McLuhan, who was pointing out that the way a message is conveyed has an effect on the interpretation of the content of the message.
Many of the symbols that appear on store and street signs, Allison's dashboard and the coded messages left by the Libra killer, are taken from the runic alphabet. These are the same symbols that figure prominently in the horror classic, Curse of the Demon (1957).