Hollywood, With Dresses
Sabrina ain't a weird, Euro film. It's not subversive. It's not out there. It's certainly not violent.
It's basically a fairy tale: Cinderella on Long Island, with Paris playing the part of the fairy godmommy.
A lot of that has to do with Billy Wilder. Wilder was an accomplished director in the plain, old fashioned, Hollywood studio system—Sabrina, like his other work, doesn't veer off course or do anything insane.
What Sabrina does is take a well-known template (the Cinderella story), give it a twist, and make it awesome. Wilder did this time and again: he perfected the film noir in Double Indemnity, he worked with horror tropes in Sunset Blvd., and he made the screwball comedy even screwier in Some Like It Hot.
And like these other Wilder joints, Sabrina is well made, but not flashy. Wilder makes no effort to provide on-location footage of Paris, for example… probably on the grounds that it would be expensive and isn't really necessary.
Other decisions are also based on the studio system, which Wilder worked faithfully within. Paramount had Humphrey Bogart on contract, for example, which is a big part of the reason he got the role of Linus.
The one exception to the unexceptional mode of production is the costuming—and in particular Audrey Hepburn's wardrobe. Many of the dresses from the film have become totally iconic.
In fact, it's not too much of a stretch to say that Sabrina changed the street fashion world forever.
The flowered, off-the-shoulder gown Sabrina wears to the dance is spectacular—but the little black dress from one of her dates with Linus is even more famous.
For that matter, even the boating outfit —simple boyish checked shirt and shorts—is a fashion coup. And what about the black ensemble she wears on her last date with Linus? That wouldn't look out of place in NYC today.
Edith Head, the costume designer for the film, won an Oscar for her work. But, as is often the case in film, the costume awesomeness was a collaborative effort . In 1952, Hepburn approached Parisian designer Hubert de Givenchy to help her create a French wardrobe for Sabrina. Givenchy had no idea who Hepburn was—her big film, Roman Holiday, was not yet out, and at first he thought she was Katherine Hepburn (a distant relation).
But he overcame his disappointment and helped her pick out the outfits that were to become her costumes for Sabrina (Hepburn herself added the famous hat to top off the little black dress.) (Source)
Givenchy went on to work with Hepburn throughout her career, and the two together turned her into one of the most famous and influential fashion icons in modern history. Billy Wilder, commenting on her waif-ish, thin form and her striking elegance, declared to a magazine in a publicity interview, "This girl single-handedly could make bosoms a thing of the past!" (Source)