The olives are pressed mechanically. This is what we called in the days of smeules de pierre "first cold pressing": it is a process during which the non-preheated oilseeds are pressed only once, at the lowest possible temperature, in order to extract part of the oil they contain.
This type of pressing preserves the nutrients in the oil (vitamins, tocopherols, essential fatty acids, pigments, etc.) as well as their aromas.