Tonneau-Shaped -- obviously a design that resonated esp. in the late 1960s and 1970s; and it has its merits:

• ergonomically wrapped around the wrist;
• optically flat by rounding-down on the edges, creating a thin appearance;
• wears quite compact by not extending the case with lugs but almost integrate them -- half-way to a disco volante;
• a huge canvas: finishing-methods, creative & characteristic designs;

Did I miss a point? At least I dont understand why it is not trending acutally.