Someone made reasonably high-quality renders of Dr. Mario, Bowser Jr., Ness, Duck Hunt, Shulk, Wario, Falco, Ganondorf, R.O.B., and Jigglypuff
They made a fake stage select screen, including never-before-seen pictures of stages. They used a leaked early copy of Famitsu as a reference, but didn't just cut-and-paste the image from Famitsu. (Note that simply having played Tomodachi Life isn't good enough: they got the room in the right position, also).
They diligently researched tiny details such as the background color of Fox's portrait, which differs on the box art, and accurately reproduced an anomaly in the thickness of a black line on the character select screen which no one noticed until it was pointed out by the leak
They made several drastic-but-sensible-in-hindsight UI changes, such as text going away with the icons this small and a whole new screen for selecting customizable characters
Now, I confess that there is no part of this which is impossible. Obviously there are many people in the world sufficiently skilled with 3D graphics to have generated those images, there are many people in the world with lots of free time and nothing better to do with it, they might have had a lucky guess / early access to Famitsu with respect to the stage, etc., but... don't you guys think this is seriously straining credibility here?
