Talking Tina is a demonstration of text to speech synchronized with stop motion animation images known as visemes.
Visemes are a series of pictures depicting a sound being made. In this case there are 24 visemes being used to make Tina's face appear to "pronounce" words.
The TTS service provided by iSpeech also supplies the corresponding viseme and the duration of the sound.
This could be developed further into a fully responsive TTS game or platform.