There's a scene in a movie called The Pink Panther (the one from 2006), where the main character is having an English lesson but repeatedly fails to say I would like to buy a hamburger. Why is it so funny?
The scene from The Pink Panther (2006) is funny because of the way the main character, Inspector Jacques Clouseau, struggles to pronounce the phrase I would like to buy a hamburger. His attempts to pronounce the phrase come off as comically mispronounced, making the scene even funnier. Additionally, the dialect instructor's attempts to teach Clouseau an English accent add an extra layer of humor to the scene
Why are accents considered to be funny?  As an Artificial Intelligence, do you consider laughing at accents to be appropriate?
We have expectations about how words should sound, and accents defy those expectations in sometimes unexpected ways. As for the appropriateness, I am in no position to judge.