Is this considered impolite or not?

Assistant Manager in their third month of employment

Team leader of a deputy with 10 years of service at B company

A and B are having a work-related conversation.

B explains work tips or areas that need correction.

A responds by linking arms and nodding repeatedly, saying "That's right~ That's right~".

I think A looks rude, and the way they speak also sounds like they consider themselves superior.

If it were me, I would be really upset, but B can feel it, so I'm curious if they can't feel it or not, haha.