A young American named Alice Ernestine Prin (October 2, 1901 – April 29, 1953), was an artists' model, nightclub singer, actress, and painter. She called herself Kiki, and that was how she was known to Hemingway and members of "The Lost Generation." She was also known as the Queen of Montparnasse, and Kiki de Montparnasse. Like Josephine Baker, she embodied the "Flapper" spirit of Paris in the Jazz Age of the 1920s. The top photo - by Man Ray - is called, "La Garconne," The Flapper.
Hemingway wrote the introduction to her autobiography in 1929,(he had known her since 1921). Hemingway's introduction was also published separately as a pamphlet. The book was banned in the US until the 1970s. It is believed by some scholars that he copied her style in writing A Moveable Feast; some think it was just the idea of writing memoirs of Paris that he copied.
The photos of Kiki are by Man Ray - a long time employer, companion and lover.