One solution is install webp-pixbuf-loader. It is a image loader for GTk+ applications.
Close Eye-of-gnome and Nautilus , then run the following command.
sudo dnf install webp-pixbuf-loader
Now:
- Eye-of-gnome can open webp images.
- Nautilus(gnome Files) show thumbnails preview of webp images.
Source from gitlab.gnome.org
webp-pixbuf-loadedr github page