At first I had posted this in the cinnamon project but they said it was a GTK issue, so I’m copy-pasting what I posted there with minor changes.
IDK the name of the application shown in the screenshots, that’s why I haven’t included it in this post here.
Issue
File selector dialog doesn’t display a thumbnail preview for WEBP images
Steps to reproduce
Go to any website that can receive images, such as imgur. Click “browse…” and navigate to a directory with a webp image in it. Click just once on the webp image - no thumbnail will be displayed to the right.
For comparison, navigate to a directory with a png image in it and click that image once - a preview of the png image will be displayed to the right.
See the screenshots gallery for better understanding what I’m talking about:
Expected behaviour
A thumbnail preview should be displayed for webp images.