You can find a PDF of the patent application here, but the short version is that Google filed a patent that was far broader and more detailed than Amazon's patent on the original Kindle or Amazon's other patent on a dual screen tablet.
Based on the figures included in the patent application, it looks to me like Google is trying to patent the widest possible variety of screen configurations, not just a single device. It's not clear to me what Google is working towards, but it does seem likely that most of the designs Google is trying to patent have already been tried on the gadget market and found wanting.
For example, this device looks a lot like the Spring Design Alex or the original Nook.
And here we have a dual screen device that would look a lot like the Entourage Edge, except that late ebook reader had a mismatched pair of LCD and E-ink screens. It also had a different hinge design, although it did have a camera and an ability to fold itself in half.
And last but not least, Google also included a device with a screen mounted on the front and the rear. No one has made a tablet or ebook reader like this, though it does share certain similarities with the Yotaphone.
According to the patent, Google is expecting that you might want to use a keyboard or mouse with one of these devices. One of the blogs that reported on this story also said that there is a mention of a camera, and while we can see it in the diagram above I cannot find of it.