What do you get when bookshelves pose for a picture?

A group shelfie, of course.

Go ahead and groan. “Shelfies” are cleverly planned photos of bookshelves. The concept is, of course, a less narcissistic twist on selfies, self-portraits that have become a staple on social media sites. (Although some shelfies have been known to include the owner in the photo as well.)

Where the shelfie idea started is hard to pinpoint, but the concept was boosted by the British newspaper the Guardian, which in December urged readers to post pictures of their bookshelves on social media and created the hashtag #shelfie to categorize the photos.

The New York Public Library took the concept further, declaring a Library Shelfie Day on Jan. 29 to encourage postings by book lovers using the hashtag #libraryshelfie. Organizers Morgan Holzer and Billy Parrott were inspired by Museum Selfie Day earlier that month, when museum employees and visitors were urged to photograph themselves in front of museum displays as a way of promoting those exhibits.

Holzer and Parrott posted shelfies every day for a week leading up to Shelfie Day to stir up interest. They anticipated getting maybe 100 submissions. By the end of the day, about 1,500 photos had been posted on Instagram and another 1,800 on Twitter, Holzer said. “It was kind of insane.”

There were photos of bookshelves arranged in rainbow order, photos of cats on bookshelves, photos of people hiding behind books. They came from individuals as well as 248 libraries and other institutions from 14 countries.

Maybe this particular selfie genre has some, ahem, shelf life? □