I believe, the reason EOG devs have implemented the current behavior is , in case the user does not like the wallpaper and wants to revert the wallpaper back to the old one.
So , instead of removing the behavior , we could move the function to the ribbon EOG uses.
The ribbon can mention
" 'Fav_pic.png' has been set as Desktop wallpaper " [Revert] [OK]
and the 'Revert' now opens the appearance prefs dialogue window.
I believe, the reason EOG devs have implemented the current behavior is , in case the user does not like the wallpaper and wants to revert the wallpaper back to the old one.
So , instead of removing the behavior , we could move the function to the ribbon EOG uses.
The ribbon can mention
" 'Fav_pic.png' has been set as Desktop wallpaper " [Revert] [OK]
and the 'Revert' now opens the appearance prefs dialogue window.