The second main feature we added for players who are watching to learn is the Player Perspective camera mode. In this mode, you select one of the players in the game, and you see the game as if you were at their computer. You see the player’s mouse cursor and input, their camera work, their HUD, their interaction with UI elements, and so on. We wanted you to be able to see exactly how a highly skilled player is playing the game, so you can see ways of improving your own play, and that’s what this camera mode lets you do.

The Practice Bots also use text chat to indicate their plans, so you can join in. For example, they’ll:

Let you know when they’re coming to your lane for a gank.
Communicate when they’re fleeing or losing a fight.
Indicate their high priority targets in upcoming team fights.
Expose their thinking about whether they should push or defend their lanes.
Call for assistance versus Roshan if they think the timing is right.