Yeah the source being just the copyright name isn't helpful. If it were a laserdisk cover though, the aspect ratio would be closer to 1:1 like a vinyl record or CD album cover, it's not nearly skinny enough to be a VHS cover. It is very close to the 1.4:1 aspect ratio of A4 paper though, so I'd be more likely to guess that this was promotional art of some sort. It seems Minitokyo had this image at one point, and they are usually pretty good at sourcing scans, but it was removed from the site. I don't see any other references that point to anything helpful after a quick search.
First of all, the KAZZ on the lower right of the image is the signature of tadano kazuko, responsible for the character design of the Sailor Moon anime.
Shinjidude said:
It seems Minitokyo had this image at one point, and they are usually pretty good at sourcing scans, but it was removed from the site.
Digging further, and it looks like this image is quite old. There are copies of various qualities from: June 2016, December 2010 and this ancient Geocities post from before 2009 (second group, second row, second to last image) Looking closer at the Geocities image and you see the number 48, which looks like the page number from a book/magazine.
+++ speculation from this point onward +++
Kazuko is a very well known artist and after searching for Sailor Moon artbooks and stuff I came across physical portfolio books, that were either self-published (doujinshi) or went through a publisher. Kazuko worked a lot with publisher Graphic-Sha which was behind the Japanese and subsequently English How To Draw Manga book series. NOT to be confused with the memetastic How To Draw Manga book that was published by Scholastic. Kazuko did the illustrations for Volume 15 which was released in 2003.
Along side these books, Graphic-Sha also released a series of portfolio books where each volume was dedicated to a single artist. These were known as Manga Artists File in Japan and renamed to The New Generation of Manga Artists for the US release. Volume 6 starring Kazuko was released in November 2004. To put these dates into context; Pixiv launched in September 2007. Besides these, there are also other artbooks that star Kazuko. One that popped up often was Tadano Kazuko Illustrations Favourite!!.
It's possible that this image is featured in one of these books.
+++ end of speculation +++
Going back to the image, what bothers me is that this image is THE best image available. Gelbooru obviously got it from here, but even the version on Zerochan (a sister site of Minitokyo) was posted 3 days after the Danbooru version and has the exact same MD5 hash. So it was copied from here. There are no other versions of this image with this level of sharpness and that do not have the retro pink hue.
Digging around with Lens/Yandex/Ascii2D/SauceNAO all resulted in nothing usable, so now I'm curious and I do have to ask: @Bibs, have you by any chance scanned these images yourself? If so, do you happen to know which book/magazine/poster they came from?
Taking the version from that old Geocities archive and doing an image search with it points to another version in an expunged E-Hentai archive of someone's Sailor Moon Tumblr site.
The Tumblr site wasn't well sourced either, but it does group a number of scans from the same sources sequentially. Looking at similar surrounding illustrations in that archive shows the cover of a 1994 Sailor Moon R calendar. The scan of the cover isn't great and I couldn't get much from that, but googling for the calendar itself revealed a well sourced Flickr album of it that does include this illustration on the page for July and August. From that album:
Item Title: Pretty Soldier Sailormoon R 1994 Wall Calendar
Calendar Size: 16.5" x 23.5"
Printed In: Japan
Released: Late 1993
Additional Info: This Sailor Moon 1994 wall calendar was made available for sale in Japan late 1993. Total of 7 sheets including the cover. Each sheet has 2 months on it.
I think that's good enough to update the source on this.