Using some post-production editing, the tablet in the picture was changed to the Nexus 7 (2013) which you can tell by looking at the wider bezel. While your first thought might be to say that this proves that the Nexus 8 doesn't exist, we have found that such quick editing often is done to hide something that was accidentally discovered. How many times have we seen a YouTube video disappear after it was leaked?
Before we definitively extinguish hope for a Nexus 8, let's hope that the swiftness in which Google made this change means that the original story struck a nerve at Google. And that could mean that there is a Nexus 8 coming.
Original picture (L) showed the tablet called the Nexus 8, which was changed to the Nexus 7 (2013) at right
Thanks, Anonymous Tipster!