These boxes allow two people anywhere in the world (with wifi) to say hello to each other in a special way. Press the button on box no.1, and the flag on box no.2 waves. Press the button on box no.2, and the flag on box no.1 waves. Fun!
If you'd like to build a pair for yourself and a friend, check out my team's instructable here: http://www.instructables.com/id/Particle-Photon-Hello-Waver-Boxes/