iMore:

Since my hands on with the HomePod, I’ve gotten a number of questions about how the HomePod deals with streaming from Apple Music, iCloud Music Library, AirPlay sources like your Mac, and if iTunes Match works at all in this crazy new world.

Here’s how everything is supposed to work.

This may or may not clear things up for you. The biggest thing I notice is that the HomePod cannot be used as a TV audio out speaker.