Originally Posted by
myfanfan9
why do LH change the curtain position when the business class is empty? It takes 5 seconds to move the curtain back and forth if needed for the next flight...

The answer I got from FA was that LH needs to show all customers that their business-class section is important, thus decided to enlarge it.
Fail to understand their logic.
The C section was probably required to be larger on the inbound. They only have to move the curtain once.
By the way, if I had paid for C on your flight I would not appreciate your self-upgrading, even though crew 'allowed' you to do so.