During a Live, it is possible to highlight a participant's video to better see his or her intervention. This feature is useful for following the discussion more easily, especially during presentations or interactive sessions.
1 - Open the Live
Go to your Board and open a Live (How do I start a Live?)
2 - Enable the magnified display
In the video tile, locate the person whose video you want to enlarge.
Click on the participant's thumbnail and stretch it to enlarge it using your cursor (bottom right of the image).
3 - Disable the magnified display
You can return the tile to the original display by moving the tile to the original area.
Good to know
Video enlargement is only for your personal view. Other participants will continue to see the default tile.
It is possible to change the enlarged video at any time by selecting another participant.
To learn more about Live's features, check out the articles available at this link.