It's definitely not a common thing for the cover artist pages. Publishers sometimes include QR codes linking to where you can buy books/merch in Japan, but we remove those as they're not relevant to the overseas audience. As mentioned above, the artist has been on a three year hiatus, and Twitter wasn't quite as much of a thing back then—at least not for Japanese ero artists. I thought it was a nice gesture to include a QR link, so we kept it in for our release.
Also for those wondering, the actual cover for this and 2019-11 should be ready next week. Sorry for the delay on those.
I'm pretty happy that the cover page and the actual release are released together!
You see a lovely cover, get curious about the content of the story, and it's right there and ready for you to read.
Also, 3 years, but this artist's work is still as great as ever!
Hope you guys can get some books of her