For some reason, this looks like a standalone feature and notes aren't added to Google Keep.
Bing Image Search used to have a scratchpad, where users could save their images.
Google also had Notebook, a product that worked well for saving image search results. "Google Notebook is a simple way for users to save and organize their thoughts when conducting research online. This personal browser tool permits users to clip text, images, and links from the pages they're browsing, save them to an online notebook that is accessible from any computer, and share them with others," explained Google back in 2006.
{ Thanks, Florian K. }