I don't either :) but sort of a silly question I guess. I presumed it was the sun due to the angle of illumination as well as common sense that the sun is probably the brightest object in the solar system along multiple bands of light; I was really just amazed at the relatively large amount of detail in the image.

Well, if the illumination was from the radio telescope, then the moon would be hidden behind the parent asteroid when it is eclipsed. We would not see it go dark, it would just be obscured.

That's just an artifact of the visualization; the point of view is above the north pole of Florence, which points decidedly away from Earth (probably +/- a few degrees from normal to the plane of the ecliptic).