Those that are not the host (account holder) have controls of their own when they're brought up to the stage. They simply need to hover over their video feed to reveal these controls.
What Are The Controls
Each guest speaker/co-host has the ability to mute/unmute themselves, toggle their camera off/on, toggle between HD quality (if their connection is strong enough), share their screen, change their camera/mic settings and remove themselves from the screen.
How Are Host Controls Different
The host (account holder) has access to each guest's controls. This means they can mute/unmute anyone, toggle their camera off/on, focus on a specific stream and remove someone from the stage. To reveal these, the host simply needs to hover over the guest's stream.