It uses several layers that many other earth models do not to give it a more realistic look.

Also the sun from the thumbnails is included in the file.
These layers include:

Artic Ice Layer 8k
Shallow Water Layer 8k
Hi-def Cloud layer 8k (the cloud layer also uses a speacial procedural effect to give it a more fluffy 3d look)

Also this is the only Earth model that uses a speacial procedural map for the ocean to give it a rich blue look with depth. Instead of a flat texture.

Other maps inlclude:

ultra hi-detail bump map 12k
surface map 4k
Hi-detail specular map 12k
Night lights map 8k (Automattically turns lights on as it enters the shadow)

Another detail this model uses that is not seen in many other earth models is a twilight zone in between day and night. Notice the red zone were its not quite dark yet, and the sun is setting to give it a red over tone.

Great care has been taken get even the smallest details to show up. Many other earth models simply apply the texture maps to a sphere model. Whereas this models uses the textures as a base and builds procedural maps on top of them so that detail is still visible even at closeups.