In Korea, they often use “yolk” as a meaning to express the important things and places.
I studied how to wrap SSD safely like an egg which covers up its yolk safely. An air bag cushion is very convenient; it is light, and easy to put the air into the cushion when it is needed. Moreover, SSD with an air bag is a safe even if it falls from a high place, and into the sea.
It is named “yolk in the cloud” because the yolk wrapped by air cushion looks like floating on the clouds.