The poor goose probably looks at the lovely profile of the Canada Goose and wonders how come its features are so soft and delicate. Notice the pretty, black beak and those soulful little eyes perched upon plumage that is pleasant to the eye. Now don't get me wrong here, I do know that Canada Geese are invasive, dirty and tend to bully, but their beauty kind of makes up for it in a way.
There is no way the poor Graylag can compare. If you look at it long enough you can appreciate its features (except for the beak that looks like a serrated edged knife). It's eyes are appealing if stare into them long enough and his feathers look soft and gentle. But yet, he knows that he is Jan and the Canada Goose is Marcia. So that is my theory. This poor bird is suffering from the Jan Brady complex.