Writing for someone who is not paying attention
The reader is not hostile and not interested. They are busy, and the work must survive that.
Most writing assumes a reader who has chosen to read. Advertising cannot. Its audience is doing something else, arrived by accident, and will leave the moment the effort exceeds the reward. This single condition explains almost every stylistic convention in the craft: the short sentence, the plain word, the front loaded meaning, the refusal of preamble. These are not signs of a low opinion of the audience. They are the consequences of writing for someone whose attention has not been granted and cannot be assumed, which is a genuinely harder brief than writing for a reader who has already sat down.
It also produces a particular kind of respect that outsiders sometimes miss. Because the reader owes nothing, the work cannot demand patience, cannot rely on the reader piecing things together later, and cannot punish anyone for looking away. Everything must be legible on a single careless pass. Complexity is not forbidden, but it has to be arranged so that a person who takes only the first layer still receives something whole. That constraint has produced some of the most compressed writing in commercial English, and it has produced a great deal of shouting from people who mistook compression for volume.
The failure mode is instructive. When work does not trust the reader's glance, it compensates with insistence: bigger, louder, more repetition inside a single piece, more instruction about how to feel. Insistence reads as anxiety and is easy to ignore, because ignoring things is what a busy person is already expert at. Work that assumes indifference rather than resenting it tends to be quieter, and tends to be the work that lasts.