When the Queen's servants are preparing Buckingham Palace for Donald Trump's visit, they place a bottle of Coca-Cola on the table. If you read the label carefully, it actually says "Cov-Fefe" stylized in the Coca-Cola font. This is in reference to a humorous spelling mistake the real President Trump made in one of his Twitter postings.
The Queen doesn't actually have any Corgis, since her last one died, she didn't replace it. She still has two "Dorgis". They are Corgi and Dachshund crossbreeds.
A letter signed by 'James Bond' can be seen on the queen's desk during the opening montage after she tickles Rex's tummy.
In the U.K. release, Jack Whitehall voiced Rex, Debra Stephenson was Melania Trump, and Dame Julie Walters voiced the Queen.
Lionsgate's seventh theatrically released animated movie of the twenty-first century after Happily N'Ever After (2006), Alpha and Omega (2010), Shaun the Sheep Movie (2015), Norm of the North (2016), My Little Pony: The Movie (2017), and Early Man (2018).