Don't panic, Gaga, the box art is probably designed by someone Ubi chose, not Maddox Games, and you know how much they like to portray a neutral historical viewpoint.
As for the crown, I believe it's a reference to the Air Ministry logo, which I think is fair enough given that the game is called Cliffs of Dover, not Göring's Guns or Eagle Day or something:
It was printed on practically everything the RAF used from gauges to lifejackets to stationery. In fact the font on the box cover itself looks similar to that used on the covers of RAF pilot's notes.
This might sound unfair, but from the perspective of Ubi (1C will publish in Russia), the American market is the biggest, and who are the Americans intuitively most likely to fly as? Add to that the fact they're a French company and you start to get a bit of an RAF spin to the marketing.
But yeah, that is some lame quickly-produced box-art.