Bro why can’t you just let crossdressers crossdress
They’re just folks doing what they love don’t act like it’s a punchline
I mean... it's complicated. It really is. This is one of the most interesting manga looking at gender there is, and the most interesting thing is that he completely identifies as being a man and likes the ladies, but just thinks women's fashion and style is fun and cool.
When I look at his coworker here, I don't see anything other than benign indifference. He doesn't get it. He didn't realize they were dudes, he didn't have a problem with the idea that they were, but he also wasn't gonna go "yeah they're super beautiful" because, well, they're dudes and he can't think of them like that. That's a step too far into attraction territory for him.
He doesn't even think that it's funny that they're dudes, just that he understands crossdressing skits more than this so he steers the conversation away from the deeply intense one where Shibata is asking him to agree with the idea that a man dressing up as a woman was so beautiful that normal women can't even come close into a more casual one about jokes.
Honestly, I don't think he thinks much at all about crossplay or even crossdressing. It didn't even matter to him, he just saw Shibata in the corner and thought it was funny. Didn't even notice, just saw his co-worker in the background of a news article. I can imagine surprise and confusion from him at finding out that Subaru was in the picture too, but not any hostility or disgust. Dude just seems too laid back.
The chapter has a sad note to it because Subaru thought he could talk about it but it didn't seem like it would've been a good idea. But overall, this wasn't a sad chapter. Nishimori didn't show disgust or distain for the idea. Just didn't get enthusiastic about it. You can't really expect much else from randos!