There is no atmosphere, ergo no light diffusion. Shadows will be crisper, lit spots will be brighter, dark spots darker. It makes sense that such differences could make an image feel "off".
What other pictures are you thinking of? I don’t recall any rovers since china’s (?) last year.
These pictures in particular are taken from a very high altitude, which may explain why they look unnatural?
Is there a reason for this or am I just tripping?