We have a new dev on the Lubuntu team and they're all sorts of gung ho... I hope they don't burn out!
Anyhow, here's a sneak peak at Lubuntu 23.04 (an interim release, not a LTS release) - with the code name of 'lunar lobster':
That's a screenshot from a Lubuntu daily image (which I was testing at the time) and it is subject to change, but I think you'll find the wallpaper remains the same.
As you can see, they took the code name to heart and I think it's one of the best default wallpapers Lubuntu has had in quite a while. The last few have been quite a departure from the traditional-ish wallpapers used over the years.
Anyhow, unless you too daily test Lubuntu .iso files, chances are good that you saw it here first.