Can "pigtail" be insulting in certain context?

I’m Chinese. Manchurian regime (Qing dynasty, 1644~1911) used to enforce their hair style upon all Chinese men, which looks like the middle one in this picture.

I know it’s called “pigtail” in verbal English, but I’ve read historical stories about Westerners & Japanese mocking Chinese people with the word “pigtail” back then. It does sound unfriendly in some sense because “pig” is not a compliment in most cultures. However, I don’t find the word insulting by any English dictionary.

So my question is, can “pigtail” be insulting in certain context, like referring to the Qing Chinese hair style in the age of imperialism? Or it’s totally a misunderstanding across cultures? Could it offend other people besides Chinese who have read those stories?