I hope I can communicate this question well as it's a subtle issue.
On a standard watch display a segment is activated (made black) to represent the part of the moon that is not seen in the night sky. Meaning a full moon would be indicated by all segments of the moon phase section of the watch not being active (not black).
On a negative display is a polarizing film simply added at the factory beneath the entire display? If so this would result in a negative segment being activated (not black) to indicate which part of the moon is not seen. That means a full moon is represented by no segments active showing the brighter of the two extremes on the watch display in complete discord with the real world.
If this is the case I would NEVER buy a negative display watch due to this illogic. I'd rather buy a normal display add polarized film and just not put it over the moon phase display. That way the full moon would be shown as the lighter of the two options.
I guess the easiest way would be for someone with a negative display watch that has a moon phase to post an image of the watch during a full moon.
Thanks for all the prompt help I know I'm going to get.