Obviously that's a different kind of picture. The planets are bright. In our one the dot is dark. Maybe becuase ours is in front of the sun and those are behind, or maybe because those are purposely more exposed to make the planets visible against the bright sun.

Does your "line of sight" diagram show the same time when those images were taken? Maybe it's a reflection off the telescope barrel? Those are supposed to behave something like that.

http://stereo.gsfc.nasa.gov/artifacts/artifacts.shtml


Who knows what that person who made the picture did to it. Have to go to the NASA site and find those original pictures to be sure. Also there seems to be one missing in the middle of the sequence.