Liza Shulyayeva discusses the implementation of a new feature in Daily's JavaScript client SDK, which allows monitoring of audio levels for both local and remote participants in video calls. The feature is demonstrated in "Code of Daily: Modern Wordfare," a social game similar to Codewords. The audio level monitoring involves methods like `startLocalAudioLevelObserver` and `startRemoteParticipantsAudioLevelObserver`, which track audio levels at specified intervals and emit events with audio data. The implementation involves updating the visual representation of participants' audio levels by adjusting the opacity of a border around each participant's tile, creating a smooth transition effect as players speak. This capability opens up possibilities for developers to create engaging features using real-time audio data.