In this promotional trailer for the film MADE IN PARIS, Richard Crenna plays himself -- or at least an actor named Richard Crenna -- who narrates a fashion show of the clothes (and the fashion models). It's only natural considering the subject matter. He then introduces us to the woman who designed the clothes, Helen Rose.
Although not as well remembered as her contemporary. Edith Head -- who also appeared in a short promotional film for a movie whose clothes she had designed, PENELOPE -- Miss Rose was no slouch herself. In her time she was nominated for an Oscar for costume design eight times, and won twice.
There's little that the studios would not do to promote their films. Why, they'd even design clothes that made Ann Margaret look sexy!