The machine is outfitted with facial-recognition software, so when a weary traveler yawns, the machine recognizes the action and serves up a hot cup of coffee. Earlier this summer, the vending machine was placed at Johannesburg’s O.R. Tambo International Airport — undoubtedly a location filled with exhausted voyagers — as a marketing event by Douwe Egberts, the Dutch coffee company. The brand’s effective ploy served up 210 cups of coffee to those willing to yawn for their caffeine.