In 1957 MGM and Stanley Donen produced a musical film called Funny Face, with Fred Astaire, Audrey Hepburn and Kay Thompson. The film was ostensibly a satire of the fashion industry and the ephemeral nature of style. But what it was also, was a remarkable picture of how completely our notions about the way we look, and how often we need to alter that, (or even that we need to alter that at all) had shifted in the post war era.
The musical number in the film that nails this concept down solidly, is the first one you see; Think Pink. The editor of the fashion magazine Quality, is searching for an inspiration for the next issue, and settles on a color theme; which sparks a massive surge in manufacturing across the industry. The implication that consumers could be motivated to ditch perfectly good items in their wardrobes, because some complete stranger told them to, is powerful, and the satire is both dead on, and viciously arch.
The final, and perhaps most salient thing in the musical number is the idea of the connection between the fashion press, manufacturers, and the buying public. It is the design community that largely calls the shots, demanding of manufacturers to make what they decide is sellable, and the buying populace is at the end, not the beginning, of that chain. Sure, if we as customers don't purchase something we're presented, it won't get presented again any time soon; but the prevalence of myriad constantly changing trends, insures that the makers of product end up winning, if for no other reason than the sheer bulk of what is out there.