David Collins posted this image to the Motorcycles 1867-1930 FB group stating that it's from an original postcard, apparently titled "Stefan Zimmermann German Fafnir engine and Fafnir carburettor".

Nick Smith replied, "If 'F2221' is a British registration, then it's from Essex County Council. The first motorcycle registered in 1907 was 'F2224', suggesting late 1906 for the registration of the one shown."

Brown's Midget Bi-Car