The corresponding image at the provided source is 1638x2048. I can not find a version of this picture at that page with a resolution of 640x800.

Either the image has been replaced within the last two weeks (despite the page itself claiming to have not been modified since 2020), or that page is not the true source.

The same is true for the parent post.

I fixed the sources on both posts. Arcana55 is referring to this link:
https://seesaawiki.jp/kagranw/d/%a5%b5%a5%ad%a5%e7%a5%a6LR

@MilkDelivery I told you before that you need to use the source you got it from, or at least make sure the files are the same. Why are you using Seesaa wiki links for everything?

Edit: I was just told that this one was an oversight and that most of the Seesaa links should still be correct.