Hey! to preface, eog tag here is meant to be for Loupe, but that tag doesn’t exist yet.
Image viewers has no dbus interface to query the default and per-folder sort order set in nautilus and the one sushi uses is only available when nautilus is active—as per Making sure you're not a bot!.
This gives a better UX because browsing in Loupe will be consistent with browsing in Nautilus. And this is how it works with gwenview and windows’ image viewer.