It's another moment Chara feels old for their age. They stay in the background, watching the two of them slide across the floor like an indoor non-icy ice rink. Even their doppelganger seems to be having fun. Wouldn't they have liked doing this when they were younger too? Lucky brat got to be with their Frisk again, assuming this is their Frisk.

What happened with theirs? Why don't they see their Frisk on the island? They're aware their Asriel is here, but...

They're not jealous--okay, maybe a little. But they do feel a little sad.