I think I know what Lewis would have said (had he lived in our digital age) to TV (especially commercials) and billboards and ads while checking email or buying groceries or sitting on an airplane. I think he would have said what he said when talking about "Progress or Creative Evolution": they
bear reluctant witness to the truth that our real goal is elsewhere. When they want to convince you that earth is your home, notice how they set about it. They begin by trying to persuade you that earth can be made into heaven. . . . [And] lest your longing for the transtemporal should awake and spoil the whole affair, they use any rhetoric that comes to hand to keep out of your mind the recollection that even if all the happiness they promised could come to man on earth, yet still each generation would lose it by death, including the last generation of all, and the whole story would be nothing, not even a story, for ever and ever. . . .
Do what they will, then, we remain conscious of a desire which no natural happiness will satisfy.
--pp. 30-31, "The Weight of Glory" in The Weight of Glory and Other Addresses, Touchstone edition