The data exfiltratiom part is after that, titled "Data exfiltration from personal devices", which yes, is a new means of transmitting data. Under the assumptions that there's no authentication to control the lights and that they have malware running on your computer already.

But my point is that the whole first section is absurd. Leaking what's on the TV via a light that shows the average color of what's on the TV? It's already on the TV. Stop looking at the light from the lightbulb and look at the TV. If you can't see the TV directly, look at the light from the TV, which is already the same color as what the lightbulb would tell you.

The music part doesn't seem any better. You know what's a good way to figure out what music someone's listening to? A microphone. Granted a light might be visible from farther away, but if someone is running party lights the music is probably not quiet.