Great photo! The surface reflection is cool, but it's your son's reaction that makes the shot - spontaneous and fun. Exactly what smartphone cameras are there for.
As for testing.... the possibilities for lulz are endless. My Z has been in two baths, a sink full of dirty dishes, a mug of tea, a toilet (empty!) and used for calls during a couple of thunderstorms. It still cracks me up to see the look of horror on onlookers' faces.