In the midst of New York Fashion Week, Mary-Kate and Ashley Olsen took some time out to meet and greet about 100 of Bergdorf Goodman’s best customers of their The Row brand on Wednesday night. While their publicists stressed the sisters were not to be interviewed because the event was “strictly for the customers,” the Olsens mingled only a little — mostly speaking between themselves and the store’s president and chief executive officer, Jim Gold. “They really wanted to take some time for the customers,” Gold said. After the huge crowds at Bergdorf’s last Thursday for Fashion’s Night Out, where the Olsens bartended, it’s no surprise they wanted to be a little more low-key. “We’re just trying to keep it mellow,” Mary-Kate said.