So.... China calls the Canadian Prime Minister "Little Potato" and the Canadian Libs think that's a wonderful thing? A compliment?
LMFAO
It's intended neither as a compliment nor an insult but merely a nickname.
The formal family name is 杜魯多 (Teluduo). Each character has its own meaning, not always flattering, but combined they make no logical sense and so have but one possible meaning: Trudeau.
However, Tudou is one character shorter than Teluduo, has a more clearly defined meaning, is humorous without being offensive, and so makes for the perfect nickname in Chinese.
To distinguish between Sr. and Jr., we add a da (big) or xiao (little) in front.
Of course this is not used in formal contexts, but serves as a popular nickname.
Storm in a teacup.
Carry on.