When there are multiple people in one gathering, a select number of video feeds will show at the top of your screen. The number of video feeds that display depend on the size of your browsing window and resolution of your screen.
You can scroll between videos manually by clicking the arrows to the left and right of the videos shown. This is called the video carousel.
To increase the number of videos visible to you or to enlarge the videos you are currently seeing, you can enter grid view by selecting the expanding arrows icon. Grid view displays up to 16 videos / screen shares in a grid format. To exit grid view, select the collapsing arrows icon at the upper right of the grid.
When someone first joins an ongoing group conversation, they will appear at the end of your video carousel. Whenever they speak, their video will show in the carousel if they aren't already visible on your screen. This helps sort the videos you see so that the most active contributors in a conversation will automatically display in your carousel. When anyone speaks, their video preview will also be outlined in green.
Enlarge a Video
To focus on one person's video (or screen share), click on that person's feed. The rest of the videos will display in a vertical row on the left of the screen. If the Build, Calendar, Chat, or Participants pane is open, collapse it for the largest view.