Remote session control.
Start a session from anywhere: at home, out on a walk, or on cellular across town. The iPhone sends the instruction once. The home device receives it and plays independently from that point forward.
The session has its own timer. When it ends, the home device stops and your phone receives a notification. Your dog's environment runs without you needing to be present or connected.
Pairing is code-based and takes under a minute. One iPhone can pair with an Apple TV and an iPad. You choose which device plays at the start of each session. If you're at home, you can also stream directly to any AirPlay speaker. The iPhone stays active during playback in that case.