Located along the bottom of the session you will find the Session Toolbar.
For Host and Co-Presenter this is what their Session Toolbar displays.
For attendees, this is what displays.
Notice, the only difference is that the attendees have a Feedback icon which allows them to send feedback in the session in the form of emojis. In forth coming releases we would like to see Host and Co-Presenter have ability to send feedback to attendees as well - pending.
Clicking on the Feedback icon, reveals the emojis menu.
Click Hide Side Panel to collapse the right side of the session.
This will expand the session allowing just the four panes to be visible.
Click Show Side Panel, to restore the panel back to the session.
Click the microphone icon from the Session Toolbar to talk in the session.
Green = Mic is accessible.
Green with line = Mic is muted.