The Beatles' "Sea of Monsters"

I just listened to the Beatles' Yellow Submarine.  The second half of this is the soundtrack to the Yellow Submarine movie, which I've never seen, and I think this is only the second time I've listened to it, but I still found something to say about it.

At about 2:22 in the track "Sea of Monsters," there's a fairly lengthy quotation of the opening of the second movement of Bach's third orchestral suite (BWV 1068).  It lasts until about 2:36.  Judging by the recording I have of the third orchestral suite (by the Academy of St. Martin-in-the-Fields directed by Neville Marriner), the quotation is pretty accurate too.  The only major differences I can find are that the accompaniment in "Sea of Monsters" is pizzicato where in the original it's done with the bow and that there are a few extra notes in the descending melody in "Sea of Monsters" before the quotation ends.

Because I haven't seen the movie, I don't know how or if that Bach quotation relates to it, but now I'm curious.