adora has no idea how babies actually work, so when finn first started smiling, she noticed that they would always smile when they saw catra, but whenever they saw just adora....their reaction was just completely neutral. finn didn't fuss or cry or seem unhappy at all to see her, but they were just completely neutral about it. It eventually led to a genuinely distraught adora complaining to bow and glimmer that her baby hated her, and them trying to reassure her that they didn't. partly because there's no reason why finn should hate adora, and partly because they're like...four months old and can't even sit up on their own yet, much less even understand the concept of hatred.

meanwhile, catra is both confused and amused by her girlfriend's behavior.