'Duck' is generally used by people talking to those younger than or the same age as themselves. In some ways it functions like the word ‘dear'.
But it's not a phrase that all native English speakers use. When Hollywood actress Angelina Jolie used it when presenting an award to an English actor from the East Midlands, Jack O'Connoll, it confused a lot of people around the world!

I can't imagine the following situation.
"when presenting an award to an English actor from the East Midlands, Jack O'Connoll, it confused a lot of people around the world!"

Please tell me the meaning!!