The guiltiest pleasure at Los Angeles international airport’s (LAX) new private terminal for the mega-rich is not the plush, hushed privacy, or the beds with comforters, or the massages, or the coriander-scented soap, or the Willy Wonka-style array of chocolates and jelly beans, or the Napa Valley cabernet. It is the iPad that sits on a counter at the entrance, with a typed little note: “Here is a glimpse of what you’re missing over at the main terminal right now.” The screen shows travellers hauling bags through packed terminals, queuing in long lines, looking harassed and being swallowed into pushing,...