I went looking for Mass Effect wallpapers, and there aren't a lot of great options out there at 1080p and higher, due to the age of the game, how divisive Andromeda was, and basically a lot of the fans have scattered. Is what it is, I guess. I did find some good ones.
Among them however, I found this gem (linked in OP). On the surface it looks like you can just change the background — it's the Mass Effect Legendary Edition cover as a wallpaper. So you can make it all Paragon (blue), all Renegade (red), or the default "split". But, click on the characters and you'll find you can change them, too! So you can put your lover at the top, or your best guy or gal. So for me it's Liara on top, followed by Garrus and Wrex (because they should never be separated), then Solus, and Kaiden and Ashley together to remind you of that choice, then I got Tali and Jack. You can change the bottom background (default is Normandy flying through Citadel). I left it alone. Lastly, you can choose between the "Mass Effect Legendary Edition" and the OG "Mass Effect" logos.
When you hit save, you get an ~11MB .PNG you can use on your desktop. That should be fine for most modern computers, but if you're pinching RAM, you can probably run it through xnview or similar and get most of the quality at 2-3MB (it IS 4K after all), maybe drop the rez down a bit if you don't need 4K. I have a 1440p monitor myself, but I kept the 4K, and it just looks fantastic.
Maybe it'll be your next Mass Effect wallpaper, but if not, it at least deserves a spot in your rotation. Your Shepard's morality (you can't take off the helmet unfortunately, so no FemShep/MascShep choice here), your crew, and your love — or not. For my paragon FemShep, it was Liara all the way (and no one in ME2). For my next play, it'll be renegade MascShep, and I'm thinking Ashley, Jack, Tali. (I don't have the "get laid in all 3 games" achievement, might as well pick that one up.) (I'm also not 100% sure Tali is an option in 3, I know she is in 2 if you're MascShep.)
Mods: I see you have an "AI generated" tag option (or the greater PieFed does?). I don't think this is AI. It's hosted on GitHub, so it's scripts, but I'm not a code monkey, I don't know what it's doing behind the scenes. I don't know if the assets are human generated or not. I figure they come from the game/official art but I'm not sure. If you want it AI tagged and can't do it yourself, kindly message or reply and I'll add it in edit. But I don't think it qualifies as AI art.