here's how you get any papes that catch your eye but are about to go past
1. make your browser windowed so you can see it ok but also have access to your desktop
2. as a wallpaper you like goes past, click and drag it to your desktop (check picture if this doesn't make sense)
3. the filename will be something like this - LR-OTU0NTQWR-WallPaperRoulette. take the part in between the LR- and the -WallPaperRoulette. in this case it's OTU0NTQWR
4. go to
wallpaperroulette.com/w/your code
5. open image in new tab and save