Coolhunters offer what they call "a window on the world of the street" — essential at a time when cool has become "trickle up", where poor black boys in the ghettoes of Harlem can dictate what a middle-class kid in Neutral Bay wears.

She makes a persuasive case, for instance, for the influence of street-fashion, generally considered a late century development, as early as the 1940s. The Harlem zoot suit for men was an early example of trickle-up trend.

Westwood-watchers can point out other instances of this "trickle-up" phenomenon. Her outsize curvy shapes resurfaced in Claude Montana's big rounded leathers.