This argument for the theoretical benefit of advertising (being informed about products/services) was probably true at the point in time when advertising genuinely consisted of a dispassionate listing of the features of a product, and maybe a picture of it. Take the commercial being highlighted here for example. It's 2.5 minutes of a very cool visual image of the toy balls bouncing en masse. But how does a zillion balls bouncing down a hill convey anything meaningful about the television model it's an ad for? How do sexy models in a commercial for beer, perfume, etc inform the consumer about the product in any actual sense?
It might benefit you to take some marketing courses to understand why these sort of ads are effective and useful. Just because you don't understand something doesn't mean there's no rational explanation for it.
(In general, it's a good rule of thumb to assume that the widespread existence of something suggests there's a reason for it, and to be inquisitive as to what that reason might be.)
He didn't ask how these sorts of ads are effective or useful. He asked how they inform consumers, which was the point someone else previously brought up as a defense.