This, for example, is a great (book) cover.
It's simple. It captures the impenetrable star with her sunglasses and leather jacket but you can't fully see her face - there's a mystery there. It says, you don't need to see her full face, even from that angle you know who it is. And the only print are the letters GAGA emblazoned on her jacket, like that's all you need to know. It gives you a sneak peek and you have to open the book for more. No explanation needed.
Perfect.
