Originally posted by AcolyteAll the other letters look the same when flipped upside down and viewed from the back This is the same as reflecting them in a horizontal plane and they all have horizontal symmetry.
Something to try with a mirror:
Get a piece of paper and write 'CHICKEN' on it. Turn the paper upside-down and hold it up to a mirror. If you look at the image in the mirror, you'll see that the 'N' is reversed - why?
N has no horizontal symmety but it goes back to front when reflected in a horizontal plane.