All it is is an animated decal. Didn't know that they could be applied as textures to DTS objects like that, but still.
You'd have to create a bunch of states, like static normal, talking, and then any sort of facial expressions for various /emotes -- and it would ONLY work with the default face, which would overwrite the uesr's preference if it was to work correctly.
I mean, in theory, it can work. But it's not a really practical idea.