Thread:HorusDB/@comment-33436465-20180718101221/@comment-32271305-20180718101727

The thumb I added is both in English and Japanese. We always upload two versions at once, and then we revert the image back once the card gets released on Global, by going to the image's page and without needing to make a new thumb or edit the page again.

Here, to be exact: File:Thumb_1003850.png > File History

If you want to revert them back to the English thumb by using that method, you can. Since they're inactive, it doesn't really matter.