Lack of ambient light and atmospheric attenuation. Significantly more direct light vs indirect light.

If you fly at 35,000 ft the horizon is at 221.3 miles and most of it is dense air. If you look directly downwards from ISS there is less than ten miles of thick atmosphere between the camera and the target.

If you do ray tracing from single light source with few objects and without effects that simulate atmosphere you simulate how the scene looks in vacuum.

I suspect also contributing is that the setting here is more like what you usually see with computer graphics than in real life. Very few moving parts.

In real life there are insects, and birds moving around. Wind blowing all sorts of things (leaves, blades of grass, trash, etc), etc. Individual strands of hair. Etc. All things we can't really reproduce with graphics.

Here there is just a sphere with a surface texture and some volumetric effects.

1) longer exposure, "averaging" neighboring pixels

2) noise reduction making it look "plasticky"

3) attempts to increase dynamic range with filters that favor certain color hues

That would be my list of possible explanations as a photographer.