Its doesn't appear paralel due to an optical illusion. There are a few threads with the details of the refraction about I believe.
Once again, not only does this optical illusion have never been explained (or reproduced anywhere) but it STILL doesn't explain how it would be at eye level straight in front of you. You do know what refraction is don't you?
Plus, if it was an optical illusion, it would be possible to just magnify the image using something like a telescope, and as you'd look at it, the illusion would no longer affect you and you would once again see a disk shape above. However, no matter how much you magnify it to eliminate the effect of distance, it will always show you a circle and it will STILL be at eye level.
How do you explain that?