The *plane* does a W pattern: ZRH-JFK-GVA-JFK-ZRH. that means that every time the plane lands in Geneva from New York, it goes back to New York, and then from there to Zürich. Suisse has timed their flights in such a way as that they have several planes on the ground at JFK at the same time, so they can swap them between Zürich and Geneva.
The *crew* deadheads between GVA and ZRH. One crew starts in Zürich, and ends in Geneva, from where it then deadheads back to Zürich. Another crew deadheads from Zürich to Geneva, and then operate Geneva to New York to Zürich.