How it works:
Broadcast to Many People
Using Twitch, YouTube or UStream services, you can share your gameplay with players who requested to watch it, and many other. You can also use your PlayStation Camera or microphone to comment on your gameplay.
Share Play with Only One Player
Share your gameplay with another player. You can share your gameplay with that specific player or hand over a controller so you can enjoy the game together.
Note: If you want to disable these requests, you can do so by going through [Settings] > [PlayStation Network/Account Management] > [Privacy Settings] > [Managing Your Friends Lists and Messages] > [Request to Watch] > and select [No One].