That's a scanning electron micrograph of dissolved salt by Signe Emma, who used it to illustrate the reason airline food (remember that? You'd have to travel abroad to eat airline meals nowadays) is so salty:
Link - via Fast Company and It's Nice That
At 30.000 feet the cabin humidity drops by 15%, and the lowered air pressure forces bodily fluids upwards. With less humidity, people have less moisture in their throat, which slows the transport of odours to the brains smell and taste receptors. That means that if a meal should taste the same up in the air, as on ground it needs 30% of extra salt.