They show up when the system is locked. They are almost all nature scenes , beaches ,mountains, lakes, etc.
Yes! I see them every day on my laptop. They are stunning!
Mine used to show them at random, but now it seems to have seized on just one.
Today’s is the slice of brisket in the sea.
Quebec, Canada / Pietro Canali
The pictures are not daily pictures, what you see each day is not what other users will see. Today’s picture for me was some rice terraces in China. The pictures provided for me stay the same for two or three days before changing to a new one.
You can hover your mouse over the camera icon in the upper right corner to see where the picture is from. Two options are noted, if you click on I like this picture it will send you more pictures like it. For instance, it is a beautiful ocean picture, if you click that you like it you will be provided with ocean pictures more often. If you click that you do not like it, the picture will be removed from the rotation on your personal device but still in the rotation for other users.
But they are some very cool pictures from around the world and I don’t think they have shown me the same one twice yet.
Same here. Something cool every now and then. Now, they just say, “Fuck It! Look at this Chinese Lake for 3 months, Asshole!”
I wonder if it’s possible to download the hi-res pictures Windows shows, many of them are stunning.
They’re doing a solid job on this stuff. IT’s not just Windows - my Apple TV, when in rest mode or whatever you call it, shows panoramas of truly staggering beauty.
Anyone know if there’s a way to make it stop showing these pictures? It’s not a huge annoyance, but they bother me. Thankfully I usually only see them right after a reboot.
You can try these steps here: How to Disable the Windows 10 Sign In Hero Image
I have Windows 10 on three machines: my home computer, my company-provided laptop, and my customer-provided laptop. On the first two I’ve changed the lock screen to be a picture of my dog, but I’m not messing with the customer settings on the latter. I’ve been enjoying those pics!
For me, yesterday’s picture – at first – was day 2 of the Andromeda Galaxy. Gorgeous.
I’ve had my customer-provided laptop since early February, and at the end of the day yesterday it started showing me my first repeat. 
There aren’t many pictures I haven’t cared for, so I don’t really mind, but I was kind of disappointed because I always like to see what’s next.
The link CoastalMaineiac provided is specifically about disabling the “Hero” background on the login screen, but the initial steps are right: Start > Settings > Personalization > Lock Screen. Then, use the dropdown to change the background to “Picture.”
My screen saver is a slideshow of pictures from Cthulhu directory. Three images show up that I would swear (on the Necronomicon of course) I never downloaded-
A boy playing what looks like a Star Wars game on a flat screen
A grey-haired professor type standbing by a wrought iron fence
An elderly woman with glasses and wavy white hair.
Either these images were added to the slideshow by Windows- or He Who Lies Dreaming added them.