When you start having to come up with explanations like this is when I start finding even believable leaks really fishy.
And why are they sending unfinished background art to some outside company in the first place anyway?
Or, you know, flip a crystal around so it's facing in the opposite direction somehow! This is exactly like that dress! /s
I made a random explanation just for you. My actual stance on the matter is we don't know and probably never will.
If it's real, it's better to not over think why art changes. The background is the one detractor out of the MANY positives for this leak.
Somehow the leaker, if fake:
- Created 7 fully original, individual art pieces that blend in perfectly with the banner and are even layered behind other characters the way it has been for months. None of the 7 are inspired by any current art out there, as far as we can tell.
- Moved 40+ characters logically and similarly to the way the banner had been updated before, to accommodate the new 7. It even has placed characters in more logical locations (Mii's together, Jiggly in a less cramped spot, etc)
- Added new art for like 20 characters that were moved because their art was hidden behind other characters.
- All of this while not showing their good work at all (posting only a quick video and picture that shows the banner extremely fast). Yes, it could be a way to hide his mistakes, but he openly posted a background that is entirely different from the one we have.
- Having the leak have an actual, legitimate source for WHY it was made or leaked. The company is real, the person is real, the printouts they make are legitimate with the same process seen in the leak.
- Not only this but he leaked it on accident and hoped it could get the ball rolling.
It's either ALL of that if fake, or it's simply the background changed for a reason we can't explain and it's real.
See what I'm getting at? It's much harder to explain why it's fake, than why it's real.