It is a little odd that Claire doesn't remember a conversion that she had with Marten and Hannelore only a fairly short time ago. I suppose that it's possible that her important bit to her was that Marten invited her to be part of his social group and the memories of the other stuff (including, hopefully, the indecent assault by the maladjusted AnthroPC) just isn't as strong. Alternately, she is as bad at segues as the Reeds are and the whole thing was an awkward introduction to her musical tastes.
I did like her posture in panel 3. She's quite comfortable around Marten to the point where her body language is getting rather flirty! I didn't think that they'd go too far in this sequence but the possibility of a serious make-out is increasing. I could see her coming home late, Clinton trying to start an argument and Mrs A silencing them both by remarking that, some days when she was in college, she'd come home days late (yes, I still like my 'Once wild and crazy Mrs A' idea).
I think that Claire has some kind of salad; we shouldn't read too much into that but I can see her pressuring Marten to eat more healthily in some point in the future.
Just to take a silly suggestion made in fun a little too seriously: I'm very confident that there is no disguise here. Mrs A is taller than Claire and Marten would have noticed. He was holding her right hand when they entered the diner; even if Clinton had put on its pseudoflesh glove, Marten would still have noticed that it was a prosthetic. In any case, neither of them could have faked Claire at work well enough (passwords, procedures and the like) to have fooled her colleagues.