Hepburn as Holly, with her hair in a high chignon and carrying an oversized cigarette holder, is considered one of the most iconic images of 20th century American cinema

Apparently it gained popularity throught the years, it wasn't so popular at the time

Holy is based on Capote's mother

The little black dress. The pearls; the oversized sunglasses and the absurdly long cigarette holder. Breakfast at Tiffany’s – the 1961 film based on Truman Capote’s 1958 novella – has become more famous for its visual shorthands, its signifiers of New York chic and fashionable femininity, than its actual story or characters.