On one feast day (usually either of the Virgin or the patron of the cathedral) the bishop is dethroned during the reading or singing of this song at the point where it talks about the mighty being brought down from their thrones and a child from the choir takes the place of the bishop to finish the service, funny hat and all.
When I was in England a couple of years ago they had recently had this celebration in that cathedral and the child bishop was actually a girl named Sophie. I love it and think it's a very cool thing.
I think it's an important commentary on the ways of the world and the ways of the kingdom and how the two don't always overlap (and then what happens!)
My soul magnifies the Lord,
and my spirit rejoices in God my Savior;
For he has looked on the humble estate of his servant.
For behold, from now on all generations will call me blessed;
For he who is mighty has done great things for me, and holy is his name.
And his mercy is for those who fear him from generation to generation.
He has shown strength with his arm;
He has scattered the proud in the thoughts of their hearts;
He has brought down the mighty from their thrones and exalted those of humble estate;
He has filled the hungry with good things,
and the rich he has sent empty away.
He has helped his servant Israel,
in remembrance of his mercy,
as he spoke to our fathers,
to Abraham and his offspring forever.