This add-on is part of a "NewTab Background" collection where background images are obtained from POTD (Picture of the Day) Websites. This add-on's creator is not affiliated in any way to the website(s) from where the images are obtained. Images are publicly available and any copyright and/or trademark belongs to their respective owners.
This is a special add-on on the collection, where images comes from a randomly generated gallery and as such the background auto-updates itself every 20 minutes.
You can automatically toggle/shuffle between this and other "NewTab Background"-based extensions by using the additional restartless add-on NewTab Background Shuffler.