onyxone Posted the above like 30 seconds too late haha.
If you want to download the cover photo specifically: right click the video image and click "inspect", then when the Dev tools shows up on the right you can click on the "console" option in the upper right, and when you see an option below with a long hyperlink ending in ".webp" you can click that link to open the image source folder (from which you can right-click and download the image).
There are many other ways to do this but the above is a pretty straight-forward option. It does assume you're using Chrome - other browsers may have different verbiage/etc.