Mueller said the Avenue Montaigne store, about half the size of the original flagship next door, is registering about 15 to 20 percent more sales than its much larger predecessor. "This store proves 100 percent that the strategy of Jil Sander is absolutely right," Mueller said.

Jil Sander is required to continue publishing financial results as it is still technically a publicly traded company in Germany. The company is engaged in a costly legal battle with a minority investor that has declined to tender a small quantity of shares in the firm.

The company has several projects in the pipeline, including the November launch of Scent 79, a fragrance with a name referencing the year of the debut of the house's first perfume. Jil Sander is also preparing to reveal a new licensing deal for eyewear, presumably with Luxottica Group SpA or Safilo Group SpA, which will boost royalty income significantly for the house.

Ferraris said he thinks the Jil Sander brand has plenty of untapped potential in areas like accessories and sportswear. To wit, the company is planning to launch a line of sneakers. Founding designer Jil Sander famously collaborated with Puma on such an initiative years ago, but this time the company plans to make the shoes in-house.

These new product categories, along with Jil Sander's plans to move into e-commerce next year, are aimed at broadening the consumer base for the brand, Ferraris said, adding the brand might consider a secondary line at some point but it's not on the table at the moment.

"It's not a priority. Our priority is to develop and extend our [product] categories," Ferraris said.