I think it has a bit to do with how they're drawn as well, Fujita is capable of drawing them the same as they were before just with eyes (seen in earlier chapters), this is usually when they're feeling spiteful. But in this chapter, for example when they're laughing, you can see that despite their mouths and eyes still being exaggerated, there's fewer wrinkles on their faces, and their eyebrows don't have that slight upturning that give them a scornful appearance.@MisterSteak, I see. I thought there would be some kind of crossover after this chapter.
@Vergift, their demeanor also got more cute, it's almost look like they were a different character compared to how they introduce in the earlier part of the story.