A cute pun and, with it, a use of the symbol @ in advertising:
A book in the shape of the letter E, not an electronic book (eBook, e-Book, e-book, ebook). Plus the attention-grabbing L@@K, now used on websites offering things for sale or rental (eBay especially, but also Craigslist, home rental sites, etc.).
(The image came to me from Michael Palmer, who got it on Steven Gatke’s Facebook page. I couldn’t trace it back from there — but Gatke has lots of stuff about books and bookbinding.)