This is an interesting snippet, and has been recently updated by Google as recently as 2023 July. Even more peculiar, Google’s own title tag for their developer page is:
“Google Images SEO: Image Metadata | Google Search Central…”
In short, by adding JSON-LD for an image, Google may add more features to Google Images such as license type, author, and more. I haven’t personally experimented too much with this but I am really interested in learning more. If anyone has seen any results in featured snippets or inside Google search with this type of schema, please contact me!