I can confirm everything that Peatisback detailed. However, my guess is that the idea of using the lounge as an "arrivals" lounge simply doesn't see a whole lot of demand given the logistics (the customer could get a gate pass from LH if the airline is willing to issue it, but he/she would have to re-clear security... hardly worth it for a free drink or quick snack??)

Still, I've seen very few things that LH will actually say NO to when it comes to pleasing a customer... especially one who flies up front.

Both sides of the lounge are physically open, but they generally don't send folks toward the Senator side until later in the day (when F pax arrive for LH443) and/or when it's unusually busy... for the simple reason that there aren't enough people to justify opening-up and maintaining both sides throughout the day. The two sides are VERY similar anyway.

I doubt the agent whom you see at the front desk has any clue how much revenue exactly they make from allowing *A partners access the club... probably wasn't that they knew and wouldn't say.

LH is BIG on branding and consistency, as I am sure most folks here know well... the furnishings, carpet, tile, you name it from the DTW club were all flown in from Germany... they use the same stuff worldwide. Actually, DTW was the first airport in the Americas to have the latest "concept" LH lounges (which have since opened in JFK, IAD and elsewhere).