As a new zealander this is my favourite map projection anyway https://en.wikipedia.org/wiki/Peirce_quincuncial_projection#...
But, 'mainland' is often used by South Island NZers to suggest that the north island (by far the most populous) is nothing more than a secondary 'non-main' island.
Semi-relevant: https://xkcd.com/977/
Also related: https://xkcd.com/1500/ https://xkcd.com/1784/ https://xkcd.com/1799/