Some male mannequins at Bergdorf Goodman have tattoos—another has two left hands, the better to grab shoppers' attention. Mannequins that arrived at Uniqlo in late March are completely see-through. Intermix's Madison Avenue flagship last week added figures that strike slouchy, casual poses.

More stores are mixing different types of mannequins, rather than using the same style throughout the store. "You're increasingly seeing retailers do a combination of abstract and real," said Ken Nisch, chairman of JGA, a retail design and brand strategy firm based in Southfield, Mich. "Having used sites and software such as Pinterest and Photoshop, the customer's mind thinks in a multitasking kind of way," he said. "They have no problem absorbing all these different mediums."