They obviously don't play literally every game or use every app, but yes, there are actual honest-to-God humans doing editorial on the App Store. (And no, they don't sell Editor's Choice spots.)
but how do they come to the decision WHICH game they play? Does a monkey throw a bunch of darts on a game release list and they then play these games and take a pick?
Of course not! There is a list that was brought together by some algorithm that said: here those games are currently successfull in either units sold or 5-stars, lets take a look at that.
This is nothing more than the technology behind the discovery queue that gets curated from the appstore.
Not your OWN discovery queue mind you, just the worldwide taste.
In Steam terms that would be just some dude looking through your recommendations and discovery queue saying: "This looks neat, try it"