The work revs up, too. During peak hours, said Jennifer Oberle Eyler, the store director at 18th Street, one associate might be dedicated to watching for the red dot on the In Stock On Shelf App that tells workers to bring out more items in that size. Another might take orders from the Ship From Store app, which effectively turns the store into an auxiliary warehouse that fulfills online purchases from store inventory rather than from distribution centers in the name of efficiency.

Christmas cheer aside, it’s a grim moment for physical retail. The nation’s offramps are littered with the skeletons of defunct malls. In New York City, retail clothing jobs declined by 9 percent from 2013 to 2018, even as overall employment in the city jumped about 14 percent. A report last week by the Center for an Urban Future found that the number of national retail chain stores in the city shrank 4 percent this year, the biggest drop since at least 2008.

Old Navy hopes to buck the trend. It has performed so much better than its sister chains in the Gap empire that Gap Inc. decided in February to spin off Old Navy into its own company — one that plans to open 800 new stores, despite a dip in sales so far this year.

But to compete in a world where Amazon moves mountains of merchandise without a retail sales force takes a particular focus, said Saravanan Kesavan, associate professor of operations at the University of North Carolina’s Kenan-Flagler Business School.

“Retail for the most part is not a place where they’re looking for salespeople,” he said. “They’re looking for retail transaction enablers.”