Google’s Satyajeet Salgar announced on Twitter that the company has launched the “book preview” feature you’ve seen on Google desktop search, now on the mobile search results. So if you are in a region where book previews are allowed, such as in the United States, and a book has previews available within Google Book search, Google will show you the “preview book” link.
Here is a screen shot from Satyajeet:
“You can now preview books on Google on mobile,” Satyajeet added.
When you click the preview book link, it takes you into a really nice mobile view of the book preview interface in Google Book Search.