THe Majestic 747 - the original Jumbo of the Sky
Paxing All Over The World
W. F.
I think that JdS has nailed this - it's the height of the walls and that the cabin ceiling is further away, due to the wider body. You are correct with 'seemed'. Of course, some of those 'pods' in First can be sooo cocoon like - that you feel cramped all over again!
... but just seemed bigger.