6 o'clock and 12 o'clock just means that the contrast is enhanced for
off axis viewing from that direction!!!!!!!

non-supertwist LCD displays don't have a very wide viewing angle.  You
can buy displays optimized for the angle of viewing that you are going
to use.

If you will always view your display head on, use 6 or 12 o'clock.

If you will always be looking at your display from a slightly lower
viewing position (like your wristwatch) then you want the 6 o'clock
viewing angle.

If you will always be looking at your display from a slightly higher
viewing position (like a clock facing you on your desktop, then you
want the 12 o'clock viewing angle.

Just imagine if your VCR had a 6 o'clock viewing angle LCD.  You would
have to look at it head on or bend your head so it was below the display
to see it clearly.  With the 12 o'clock display you can still read it
standing up away from it.

Does this clear things up?
Dave