Google Docs uses a URL based clipboard method to copy/cut and paste images and other media. That happens to works great between Google Docs but it completely fails when I try to take images from Google Docs to my Jekyll Posts when I need an actual image file. This is a small things but took some digging to figure it out for both Windows and MacOS.
You are forcing Google Docs to provide direct access to the image object in the web browser. I’ve done this with Chrome on both Windows 10 and macOS Sonoma successfully.
From here, you have options on how to save the image back to the operating system file system. Be aware that the other options for “Copy image” and “Copy image address” just get the URL of the image not the actual image to the clipboard.
open google document
double-click the image
press shift + right-click the image
"open in new tab" then save image using browser
or
"save image as..." to save image
Hope this helps someone else in the future or me when I forget how to do this in six months.