The following description is on the back of this postcard:
The new surface cars now so numerous on Broadway were first introduced in 1914. The central portion of the cars is built close to the ground and the doors are in the center of the car, the steps being only about 6 inches from the ground.The hobble skirt cars got their name from the women's fashion of hobble skirts, skirts with narrow hems that made it difficult for the wearer to climb into a streetcar. The low floors on the hobble skirt cars made it easier to enter the streetcar.
More information about the hobble skirt cars can be found on Tramway Information.