I would think that copying is much like copyright, the Queens head is an official figure so therefor cannot be used willy nilly on a coin, permission would have to be granted, same goes for the REV is using a design from a previous type coin, so in summary, perhaps some royalties are paid, and therfor countries are happy for these designs to be used in these cases, you shouldn't just think it's been used however they please which is where i think you're coming from.
Couple that with the fact the Queenies effigy is done by IRB i think it's unlikely that it's just been thrown together by a mint.
Niue Silver Coins
A tiny country in the South Pacific Ocean with a population of just 1,600, the island of Niue lies 1,491 miles northeast of New Zealand within the triangle formed by Tonga, Samoa and the Cook Islands.
But despite its small size, Niue has recently emerged as a big player on the world's collectible coin market – releasing 99.9% pure silver coins with officially licensed designs that feature everything from the classic Star Wars characters to Disney favorites like Mickey Mouse, Donald Duck and Cinderella.