Just took a screenshot to preserve the offer...
I wonder how the response will be in these times (the trial runs till mid December) where everyone is getting this facility anyway (minus pillow, blanket, matress pad).
Also I must admit I have not done LH Y longhaul since 2012 so I'm not really up to date with the seats, but from my own painful self experiments flying whY in the past (2004-10) I remember that the seat belt buckle was difficult to move aside. The arm rest on the B744 3-seaters went up fully like shown but the 4 seaters in the middle were rather stubborn in the A343 and B744 and you couldn't fold them up. So maybe the 260$ includes the magic key that unlocks the arm rests