Over the years I have seen many different "styles" for taking an extra passenger on a bicycle, including this one scene in this picture from 1921. For this style, the passenger rides sidesaddle on the bar in front of the driver. This works OK for a smaller passenger. Most of the bicycles like this one that I remember had some sort of rack behind the seat, and a passenger could sit straddling the rack. The worst technique that I have witnessed, which almost always ended in disaster was to have the passenger ride seated on the handlebars, with legs straddling the front wheel, and feet resting on the tine nut on each side of the front wheel axle.