When Jonathan Cohen stepped into his role as J. Mendel’s first resident designer in September, it was crucial for him that his work not be viewed as an extension of his eponymous label. That separation couldn’t have been clearer at his debut runway show for the brand, which took place on Wednesday at the top floor of the One World Observatory in New York.

“I’m not trying to do Jonathan Cohen at J. Mendel,” he told Fashionista backstage after the show. “This is a J. Mendel collection, and my job is to really go in a new direction for both myself and the J. Mendel brand. I’m looking at who the client is, who the new clients could be and where those wardrobe-building aspects could be enhanced.”

Where Cohen’s eponymous brand is defined by its vibrant colors, floral prints and subversive design details, the designer’s debut J. Mendel collection homes in on the legacy brand’s penchant for craftsmanship.…