Pikmin 3 was orignally being developed as a wii game. It only renders at 720p and upscales to 1080p (actually says this on the japanese cover). It is also missing anti-aliasing. It doesn't matter how the miiverse thing works if that is not actually graphics in motion. It's quite possible if you pause the game the wii u can do additional processing of the a still image to render it at a higher quality. Any console can do this and the process is well known from the days of Babylon 5 where images were created slowly due to lack of processing power to render them in full motion. It's not much different to pre-rendering if you are only applying extra graphic detail to a still image.
This is all basic stuff that shouldn't need to be explained. You should only compare full motion game graphics to be fair, not pre-rendered or still images. Unfortunately 3dude is not fair, accurate or honest in his views so this thread has basically turned to garbage.