It's called a courting tandem and the captain rides in the rear position, which is why the rear saddle sits higher on the frame.
Note that the front bars still 'steer', but steering is 'controlled' from the rear.
If you'd really like to get into some esoteric tandem trivia, let me be the first to twist your head around the idea that the captain may actually be the chauffer or "stoker".
A chauffeur is an individual who operates any self-propelled vehicle for a profession. While the term may refer to anybody who drives for a living, it usually implies a driver of an elegant passenger vehicle such as a horse-drawn carriage, luxury sedan, motor coach, or especially a limousine; those who operate non-passenger vehicles are generally referred to as "drivers" and truck driver. In some countries, particularly developing nations where a ready supply of labor ensures that even the middle classes can afford domestic staff and among the wealthy, the chauffeur may simply be called the "driver." "Chauffeur" is the modern French masculine term (noun/verb) derived from the meaning "he who heats". The earliest automobiles, like their railroad and sea vessel counterparts, were steam-powered and required the driver to pre-heat the engine to produce energy, thus, the French term for stoker.
Note that horse-drawn carriages and steam-powered trains pre-date bicycles, thus the term 'chauffeur' (stoker) was well defined before it may have been applied to tandem bicycles where, it is fairly easy to suggest, the one who steers, brakes and otherwise makes sure the machine is operating is the 'chauffeur'.