Using Firefox 144.0.2, usually when directly loading an image into a new tab hovering over it still shows the image info. But in some cases, it does not, even when it did for the same image when embedded in a web page. Unfortunately, I've been unable to identify a cause. It doesn't appear to be the extension (filename or URL) nor the MIME type, but it does seem to happen more on gifs/animated images.

Here's an example that works in webpage¹ but not directly².