The thing that troubles me is this: who answers their door knife in hand? Obviously, Hanners was about to
sacrifice open the melon when Marten rang, knocked, or what-have-you. Normal behavior would be to sigh, put down the knife, and then go to the door.
Of course, I was taught as a child (nevermind how) not to walk around with sharp objects in my hand. Perhaps, in space, no one cares what you puncture.
Since Marigirl is invited, why not use Momo-tan, who has holographic projection equipment built in?
They don't know she's coming. Note Marten made sure Hannelore was coming before he made his request. Awfully polite fellow, that Marten. Doesn't say 'Hello, Hanners, how are you, and
why have you got a knife in your hand, for the love of god, don't stab me, think of Dora—she'd really fuck you up if you did that, you know. I heard that Vespavenger chick still doesn't walk right."