American actress Marilyn Monroe on the set of Gentlemen Prefer Blondes, directed by Howard Hawks. (Photo by Sunset Boulevard/Corbis via Getty Images)

You undoubtedly already know that the gorgeous Marilyn Monroe in this iconic photograph was captured during the making of The Seven Year Itch. There is more to the story than that, though, such as the reason she posed with her back to the photographer.

The photographer was a man by the name of Sam Shaw, who also served as a couple of the films’ production companies’ set photographers. His photographs were used to promote the movies he photographed. Shaw first met Monroe while working as a set photographer for the movie Viva Zapata!, and the two quickly grew close.

Shaw had a knack for creating powerful pictures that made an impression. It should not be surprising that he chose the subway grate scene from The Seven Year Itch to advertise the movie as he had previously experimented with the idea of employing wind as a technique to depict the whimsical spirit of his subjects. In the scene, Monroe and co-star Tom Ewell were seen leaving a building; as they did so, Monroe’s skirt became entangled in the updraft of a moving subway car. Both on location and in a studio, it was shot.

Monroe stood over the subway grate while the sequence was being filmed in front of both the press and onlookers, enabling the air to dance feistily with her skirt. Naturally, Shaw was in the spotlight, taking pictures of Monroe as she acted out the scene with Ewell and whenever she halted between takes to pose for the media. Shaw’s granddaughter claimed that Monroe once turned to face Shaw directly and exclaimed, “Hi, Sam Spade,” referring to him by that moniker.

It was that exact moment that Shaw captured in this well-known photograph, which has fascinated generations.

Knowing the history of this iconic picture will help you remember it every time you see it. You’ll be able to see the enormous actress pausing to recognize a friend and ending the salutation with a tiny smile.