This bird courtship video is very entertaining. Click the play button below to see how birds show their affection.
Obviously the first bird in the video is the male finch bird and it is dancing as a form of courtship towards the other bird. You will see first that it is shaking its head (like a rockstar) facing down. He moves it slowly upward then started hopping on the perch while trying to be closer to the female bird to attract her.
This is gesture shows how finches court their partners before mating. You will also hear the female finch chirps while the male dances.