When engaged in a video conference, you can share your screen and present for other members.

To begin, join any Live Room you have access to. Once there, click the screen share button in the bottom as illustrated below.

This brings up a new pop up. You have option of sharing an entire screen, a window, or a specific tab on Chrome.

In this example, an entire screen is shared.

Once the screen is shared all meeting participants will see it. In this view, the participant's camera (only one) is turned on as well.