When comparing XnView vs Eye of Gnome (eog), the Slant community recommends XnView for most people. In the question“What are the best FOSS image viewers for Linux?” XnView is ranked 4th while Eye of Gnome (eog) is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro Supports over 500 image formats
Pro Includes simple editing tools
Typical image editing tools are included. For instance, there are tools for color and size manipulation, several filters and effects.
Pro Available for macOS, Linux and Windows
Pro Easy redate and view configuration
Pro Compare images side-by-side
To delete blurry phone pics, etc.
XnView speaks over 30 languages.
Pro Portable version for Windows available
Pro More lightweight than other kde or gnome dependent applications like gwenview, gthumb or kphotoalbum
Pro Double-click to view Fullscreen
By default, double-clicking on the current image opens it in Fullscreen mode. This can be turned off in Preferences if desired
Pro Image Slideshow
You can view a slideshow of all images in the current folder, and adjust the delay between images in the Preferences dialog
Pro ESC key exits Fullscreen and program
Pressing the ESC key exits Fullscreen mode, as well as exits the program ... hence press the ESC key twice and you're out
Pro Can set image as wallpaper
You can set the current image as your desktop wallpaper directly from within this program
Con No Dark mode
Con Very poor quality and very invazive on windows 10
Convert all images to 8bit rgb
[not suport 16bit or 32bit, cmyk, Lab, multichannel] so you never be able to see real original image, you only see the result of conversion...on windows 10 it enforced self promotion to default app for every type/format of image...
Con No custom installation - if you need i.e. a language package, you need to install the full version
Con Free only for private use
For use in a company 1 license starts at 26 EUR.
Con Doesn't show movies on phone in correct position
Some of mp4 files shows in upside down position.
Con Doesn't pan/zoom fluidly with touchscreen
Con No APNG support
And it won't be it seems https://bugzilla.gnome.org/show_bug.cgi?id=151281