This is where the Mercator projection's distortion is at its most spectacular. Near the poles the map magnifies area several times over, so the worst offenders aren't merely a little too big — they're drawn at a wildly different scale from reality, turning modest landmasses into apparent continents.
Greenland is the poster child: it looks a match for Africa, Australia or South America, yet Australia is about 3.5× its size and Brazil nearly four times. Even genuine giants get inflated — Russia is drawn as if it could swallow five or six Australias when the true figure is about 2.2×. Drag any of them toward the equator to see how much of their bulk was never land at all.