It’s a classic quandary among those unsure of whether they’re witnessing a hot trend or a train wreck: Did she mean to do that?

When Anne Hathaway and Jennifer Lawrence wore their necklaces backward at the recent Oscars, some suggested that a trend had been born.

Not so fast, said Tara Murphy, managing director of MNfashion, who noted that letting necklaces course down your back was very much a look of the 1920s and ’30s. Coco Chanel often let multiple strands of pearls caress her shoulder blades. Nicole Kidman wore one in a 2007 ad for Chanel No. 5.

“But it never really caught on,” Murphy said.

Still, the trend may be near, although no thanks to the Oscars.

Wait until this summer, when Baz Luhrmann’s “The Great Gatsby” hits movie theaters. “I’ve seen the costumes,” she said. “If anything will bring back the look, this will.”

For starters, the movie will show how to pull off the look properly, Murphy said, meaning with a nearly backless dress worn by a woman with a curvy spine and spectacularly toned deltoids. To her eye, both Hathaway and Lawrence were fashion “don’ts” because the proportion of gowns to jewels wasn’t right. It is, Murphy said, “a tough look to pull off.”

So beware, would-be fashionistas, if you think this merely is a matter of whipping around your necklace, especially in places like Minnesota, where strangers blithely tuck in errant shirt tags.

“Yeah, you’re going to risk a lot of, ‘Oh, honey, let me fix your necklace for you.’ ”