The extension adds a menu item so that you can try to copy the GIF image as HTML.
Whether or not pasting works depends on the application being pasted, not all applications can be pasted in HTML format.
## Technical details
Chrome can only copy the bitmap to the clipboard, which means that GIF animations will be copied as a single-frame image.
Copying a GIF as HTML is an alternative method, the clipboard content does not contain the image data, only its hyperlink, and the application that is pasted needs to fetch the GIF image.
You can also select a section of GIF image that contains text and use the browser's original copy command, which is the same thing that the extension does, with no essential difference.