One of show business's most glamorous – and notorious – images, there's more to this 1957 snapshot of Sophia Loren and Jayne Mansfield than might first appear.

On the night of Sophia Loren's "Welcome to Hollywood" dinner party in April 1957, Jayne Mansfield walked into the exclusive Romanoff's restaurant in Beverly Hills with a plan. The swanky soirée being thrown by Paramount Studios was packed with some of the biggest Hollywood stars of the era, from Barbara Stanwyck and Montgomery Clift to Gary Cooper and Shelley Winters. But it would be a candid photograph of Mansfield and Loren that would earn the evening an indelible place in Hollywood history.

According to Eve Golden, the author of Jayne Mansfield: The Girl Couldn't Help It, Mansfield wanted to make sure all eyes were on her. Signed to a seven-year contract by Warner Bros. in February 1955, the then 24-year-old blonde former Playboy Playmate was seen as a rival to Marilyn Monroe, who had been "causing problems" for 20th Century Fox, Golden tells the BBC. Released just eight months apart, the huge success of The Girl Can't Help It (1956) and Will Success Spoil Rock Hunter? (1957) quickly established Mansfield as a star.

Sophia Loren was just 22 when she arrived in Hollywood. Born and raised in Italy under Mussolini's fascist regime, Loren's mother had her "own theatrical ambitions", says Mary Ann McDonald Carolan, author of The Transatlantic Gaze: Italian Cinema, American Film. Loren entered beauty competitions as a teenager, where she met her future husband, the film producer Carlo Ponti, before she enrolled at the national film school of Italy. Ponti produced many of her early films. Post-World War Two Italy was swamped with Hollywood productions, too, as studios took advantage of the country's lower production costs. "There was an extraordinary amount of artistic, economic, business, and cinematic exchange between Italy and America at that time," Carolan tells the BBC.

After the success of 1953's Aida and 1954's The Gold of Naples, which screened at that year's Cannes Film Festival, Paramount signed Loren, betting she could follow in the footsteps of her European counterparts Leslie Caron, Ingrid Bergman, and Marlene Dietrich.

By April 1957, it was time for Loren to make her debut amongst the Hollywood elite at Romanoff's, where Mansfield was the last guest to enter. She walked in covered by a "great big fur coat," says Golden. When she took it off she was wearing a backless, extremely low-cut satin dress, which she knew would draw the attention of everyone in the room, particularly the photographers. "She sauntered over and plumped herself right down next to Sophia Loren," says Golden. "It was definitely planned. Jane knew exactly what she was doing." Photographers Delmar Watson and

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