According to the developer, XPEarth is “…a Lod Controlled Photorealistic scenery designed using 15 m resolution satellite images which are perfect for design photorealistic scenery to be displayed at Lower LOD or at further distance from your plane position. This is the first Ever scenery of this Kind Designed for Xplane.”
It’s also slightly unusual in that it is actually invisible around the aircraft position, only becoming visible around the 4-6 mile mark – a circle which gets smaller as aircraft altitude increases and larger as the user aircraft descends. Needless to say, this isn’t designed to be close in scenery, it’s designed to increase world fidelity around you, while allowing the default scenery to blend in for better visuals up close. Take a look here for more information.