A ways back in this thread, I posted an image showing that the circle and the grid in the symbol don't line up. Someone kindly pointed out that the way the image was "stretched" could cause some misalignment.
So, I went back to the image, and set out to prove that it wasn't incorrectly stretched. To do this, I focused on the grid under the assumption that it is intended to be symmetrical. I used two different sources (images), one from the front page (blue) and the other... I don't know where I got it from.
The following image shows that the signal has been "stretched" to create a close proximity to a circle. I still point out that the grid center and the circle center ARE NOT ALIGNED. The rest is just me playing around seeing what fits...
http://i.imgur.com/1LuTGGk.png
Here is my attempt to align SYMMETRICAL ellipses across the grids:
http://i.imgur.com/7vhdtze.png
You will notice, the ellipses in GREEN match up as well. The ellipses in YELLOW do not. I lined them up in the top hemisphere, and they do not line up in the lower hemisphere.
So I went back to the image with the elliptical profile instead of the circular one. Note, once again, the ellipse center and the grid ARE NOT ALIGNED.
http://i.imgur.com/mUznxnF.png
And here is what it looks like when I try to align SYMMETRICAL ellipses across the grids:
http://i.imgur.com/CSxum1y.png
Again, the GREEN ellipses match up well. The YELLOW ellipses do not.
At this point, I wonder if the purpose of the grid is simply to verify if the image is properly scaled in X and Y as well as representing a spherical body (otherwise, why not use a square grid to establish scale?)