The vending machines work for Android 4.0 smartphones that have NFC capabilities. The touchscreen displays the 18 different gaming apps (both free and paid) the machine is promoting. Acquiring one of them is as easy as dropping your phone on a tray.
Though this maneuver seems a little gimmicky, it will likely go down well in Japan, where you can buy a truly astonishing variety of things from vending machines. It's also a clever way to promote not just Google's Android phones but also the apps that bring the devices to life.
Whether the vending machines will make it overseas is unknown, as Engadget points out, but here's a great question: Would you buy apps in this slightly old-fashioned manner?