This is a very cute little video. It is not actually a video but what is called an animated GIF. It is a series of photographs strung together, which are presented rapidly one after the other. automatically. This, after all, is what a movie is. Only in this instance the quality is not that good because the individual images have to be quite small because there are a lot of them and taken in total they represent a very heavy file.
I like this animated GIF because it is hard to escape the conclusion that this sweet dog has deliberately stepped in to defend what seems to be his friend a cat who was, on the face of it, being bullied or pestered by another cat in the household. Enjoy.
To me, without being sentimental and without anthropomorphising animals, the behaviour of this dog strongly indicates a friendship with the cat that he protects, which confirms a lot of things about companion animals, namely that they have emotional connections with other animals and therefore have emotions and sentiments towards animals and feelings about the behaviour of animals that are within their sphere of activity. This dog is doing something that looks very human.
An alternative assessment is that the dog is mediating a dispute like a referee that being his role in the family.