GMB Bulk: Do image URLs hotlink or are they hosted by Google?

[Justin Mosebach]

When doing a bulk upload spreadsheet and including image/logo URLs, will those image URLs always need to stay the same in the future? Or, is Google simply going to the image file one time, downloading it, and then hosting it?

IOW, I'm trying to figure out what happens if an image URL would change in the future - does it even matter?