Some British people use the term "yanks" in a positive way, as a way of expressing admiration for American culture or achievements. For example, someone might say "I love American movies, yanks make the best films." In this context, the term is used as a way of acknowledging the contributions of American filmmakers.
However, the term "yanks" can also be used in a negative way, as a way of expressing criticism or disapproval of American culture or policies. For example, someone might say "I don't like American politics, yanks are always interfering in other countries." In this context, the term is used as a way of expressing frustration or disagreement with American actions.
It is important to note that the use of the term "yanks" is not always offensive, and it depends on the context in which it is used. In general, it is best to avoid using the term if you are not sure how it will be received.