Has Claire had a reason to smile?
I mean, we've seen her in two strips since her last smile. In the first, she had something serious to say and didn't get a serious reply, on screen.
In the second, she's concerned about how her boss is going to react, and how her new thing is going to go over socially. At the end of both, she's reacting with some flavor of surprise.
The door is still open about Marten responding to her serious statement with something less than serious. On balance, I would guess that isn't going to be an issue. It could have been. It might still be. (Seriously. People--especially men--undermining their SOs and calling it playful is a thing. Claire probably doesn't have the experience romantically to see that side of it. Otoh, men "playfully" undermining women as a form of social dominance is also a thing, and it's logical to assume Claire should be familiar with that. She was a man four years ago, regardless of how she identified. She has direct experience with the different ways men and boys are treated and undermined in social contexts. It's like the FTM scientist who overheard peers discussing how much better his work was than his "sister's." People react with unconscious bias.) If Claire does have a problem with Marten's behavior, we'll find out. But, at the moment, it seems she doesn't.
It's just too early to be looking for patterns, IMO. If something happens, it makes sense to wonder "what now?" But if something isn't followed by something else, it's just another data point.
If Claire had reason to smile in the short time we've seen, I might think something was up. As it is, l don't think she's had a reason.
Keep in mind, we've seen a few seconds of at least several minutes. We don't know what we've missed.