I feel a bit bad for the servant, really. Sees the princess as a sister figure, and has put her life on the line for her, but everyone's just like "haha, she's like a dog!" or just completely oblivious to the possibility of thinking about her that way.
Also kind of weird since the villainous fiance, when showing off just how much of an asshole he was, referred to her as the princess's "pet dog", so it's kinda strange to have someone in the MC's party say the same thing as a lighthearted joke.