This nightstand is not completely waterproof. All wood construction materials are protected by a layer of paint that keeps it safe from momentaneous water contact. If water persists for longer periods of time, it might humidify the wood and cause permanent damage.
The electronic boards are located inside the plastic shield, but this doesn’t ensure to be waterproof. The most exposed circuits are the ones located at the top (tops lights and USB ports). The electronic boards have some protections to cut the electric current in case of water but do not ensure that some permanent damage might occur.