Life is like a library owned by an author. In it are a few books, which he wrote himself, but most of them were written for him.
--Harry Emerson Fosdick
Recently YA reading shows a trend of cover art -- head shot of a girl lying down. I am not the first trend spotter. Elizabeth Bluemle wrote about it for Publisher's Weekly in 2010: The Season of Windblown Hair — Or, the Zeitgeist of Book Covers. I hope to update as I spot more recurring themes.