To help spell it out for those who keep misunderstanding, when the Queen visited the USA in 2010, she did it as Queen of Canada, under the Canadian flag, with Canadian staff and security.
> Even though the crowns are distinct, the crown resides primarily in the UK, no?
Nope. Wholly domestic in Canadian law.
> This division is illustrated in a number of ways: The sovereign, for example, holds a unique Canadian title and,[82] when he and other members of the royal family are acting in public specifically as representatives of Canada, they use, where possible, Canadian symbols, including the country's national flag, unique royal symbols, armed forces uniforms,[87] and the like, as well as Canadian Forces aircraft or other Canadian-owned vehicles for travel.[88] Once in Canadian airspace, or arrived at a Canadian event taking place abroad, the Canadian Secretary to the King, officers of the Royal Canadian Mounted Police, and other Canadian officials will take over from whichever of their other realms' counterparts were previously escorting the King or other member of the royal family.[88][89]
