gtk softwares need gdkpixbuf image loaders to be able to display images (jpg, png, svg, ...) if you want that to work you need to - include the loaders - generate a cache (or ship a static one in the source and copy it) - include mimetype definition (or a static mime.cache) so the loader knows what image type is needed - set those environment variable "# Gdk-pixbuf loaders export GDK_PIXBUF_MODULE_FILE=$SNAP/usr/lib/$ARCH/gdk-pixbuf-2.0/2.10.0/loaders.cache export GDK_PIXBUF_MODULEDIR=$SNAP/usr/lib/$ARCH/gdk-pixbuf-2.0/2.10.0" ideally snapcraft would do that for you