Queen's Image On Australian Commemorative Coins Likened To Shrek

I don't see a strong resemblance to Shrek.

However, it is absolutely part of the coin designer's job to ensure that the artwork will represent itself well on the final struck coins. I think that is a great weakness of all the recent U.S. quarter and dollar designs—they are made to look good in artwork and on proof coins, but the business strikes are jumbled and lackluster.

Maybe it is the two hair whorls that vaguely look like Shrek's ear stalks?

did she have a chipped tooth?

This kind of thing is generally what happens when a photograph - even an excellent photograph - is used as the primary basis for a coin design. The William and Catherine wedding 20 cents coin is another one that comes to mind:


In both this coin and the OP coin, I think it's the teeth that are triggering people's uncanny valleys and putting people off - they look way more pronounced than they would in real life (or on the original photograph).