https://blog.angularindepth.com/https-medium-com-thomasburleson-animated-ghosts-bfc045a51fba

Thomas BurlesonBlockedUnblockFollowFollowingDec 10Using Ghost Elements in your UXPerhaps you have already heard of this concept: UI skeletons or ghost elements?

Sometimes referred to as ‘skeletons’, ghost elements are gray-box representations of pending UI that will be available in the future… once your async data has loaded or perhaps a lazy-loaded module is ready.