This is a little site that displays some of the Google Chromecast background images. I scraped them from Google's publicly available Chromecast homepage.
Unfortunately, Google has not provided this information for the majority of the photos used for Chromecast backgrounds. If you are dying to know more about a given photo, you can do the following:
Many of the backgrounds are for sale on other sites or are not available in multiple formats. If you're looking for satellite imagery you should check out SatDrops.
I have no idea. I'm not affiliated with Google or the Chromecast product in any way. You might start by reaching out to Chromecast support to ask them. The intent of this website is strictly to feature images from the Chromecast.
The purpose of my site is not to violate terms/copyright. If you have a problem with a photo on the site please let me know and I will remove it immediately. In 5 years I've never once received communication about this though.
Good question! Hosting big files like this is not cheap so I've disabled bulk downloading. You can try reaching out though and I'll see what I can do.