I always liked that scene. It gives Gandalf a very grounded personality. He may have incredible magic, but joy is its own magic.

When he goes all terrible power when Bilbo offers him the ring, it makes the line “I am trying to help you.” hit harder. He is genuinely a friend trying to help instead of some conniving trickster. He goes loud to make sure Bilbo is listening for the quiet part. With an insidious ring whispering to you, it can be hard to hear!