As a graphic designer /illustrator or whatever I am, arguments about graphic effort, Grinch stuff around, differences in the backgrounds, or whatever related is a sure dead end. I know how that **** work and how most of these arguments got an easy an credible counterpoint.
There could be more than one background version for various formats making easier the work or just for personalitation addding characters or logos (pop-ups, posters, cards, circular **** like the one which is shown, screen stuff...) a graphic designer can work very well without being good at drawing, (somebody who only control the press even better) or being someone very good at it who works in a small print company. The print papers shown in the french video also means nothing because most of the printed work looks the same. Our French friend could work as designer or quality inspector checking early versions like the ones shown in the leak. There could be confidential work between the company and Nintendo, so don't wait for a conection, (not even about past works, those documents can be very restrictive) VG companies are really serious about this. It's difficult for some people make a fake banner, not for everyone. Etc, etc...
Don't follow this way, you can't prove anything according at what we got.
Just wait to the reveals or bigger leaks.