That would be the charitable reason, but I wonder if it could be more related to their laws on accurate representations in ads (Act against Unjustifiable Premiums and Misleading Representations [0]).

[0] https://www.japaneselawtranslation.go.jp/en/laws/view/2303/e...

Please don’t compare a beautiful practice with the symbol of ultra-capitalism.

Probably it’s some sociopathic psychologist working for McDonalds that find out that askew buns makes them sell 0.2% more units per year, which is around half a gazillion dollars in increased revenue.