The Beatles' "I Feel Fine"

Because I'm doing a separate project where I'm looking into the Beatles' music, I'm working on my transcriptions of the songs as I listen to them.  I'd already completed "I Feel Fine," but in following along in the lyrics, I noticed the backing vocals during the bridges:

I'm so glad that she's my little girl
She's so glad; she's tellin' all the world

The backing vocals double the "I'm so glad" and "She's so glad," but for the rest of the line, they're just "ooh"s.  There's a bit of parallelism between those two sections in the lyrics, but having the backing vocals double those nearly-identical parts helps to further the feeling of completeness that the relationship has and that the lyrics already describe.