Presumably you answer it via speakerphone? I would expect (in a real product, not this) that the laptop and monitor shells would have speakers and microphones

Presumably you answer it via speakerphone? I would expect (in a real product, not this) that the laptop and monitor shells would have speakers and microphones so the whole setup could be a phone. It's not that different from your iPhone ringing during a game of Plants vs. Zombies.