I don’t know what a .webp file is but I don’t like it. They’re like a filthy prank version of the image/gif you’re looking for. They make you jump through all these hoops to find the original versions of the files that you can actually do anything with.
That is correct. They are open in ImpressionEyes. I can drag them by clicking on them. I can right click on them to open the viewer menu. I can cycle through images in the folder they were opened from by press next and previous, etc…