You have to remember that this is a documentary made for humans, and the narrator is trying to create an emotional hook for the human.

In reality, the social interactions of other animals are so different from what humans know that it does warrant some sort of explanation for the uninitiated.

That's not to say that, for example, your cat doesn't love you, it probably does. But it will display it it in accordance to the norms of a cat, which sometimes include bringing in dead mice as an offering, something that will annoy first time cat owners.