The Porteur style of bicycle popular by newspaper delivery men in France in the 1940s-1960s had reverse brake levers, seen here in this diagram from an article from Bicycle Quarterly (the photo jpeg is titled rebourherseville1960.jpg):
Was this just purely for style reasons? I can't think of many advantages of a reverse brake lever (except style) and can think of major disadvantages (it will hook or catch on things as you move forward). What were the rationale for having brake levers like this originally?
Period sources preferred.