fanart from the look of it.
The style isn't typical of professional animation, manga illustration or visual novel CG.
Given the coloring methods used there (favored in the Western community but not typically used in the Japanese one) and the facial design of the characters in the Gundam pic: I would go so far as to speculate it's probably NOT Japanese in origin. I would poke around Deviant Art for your answer.
This is one of the many reasons people need to stop reposting fanart without permission >_< No one can ever figure out where it came from later.
edit: one is signed "Hubert De Lartigue"... a websearch indicates that he may or may not be a professional pinup and nude artist (making the posting of a site a little shady).
Moving to general anime forum...