Activity indicators let you see who is drawing and annotating in a call. The avatars of the participants or the initals of the device are displayed when someone is interacting with the whiteboard, so you can follow who is drawing or annotating.
Activity indicators are enabled by default. You can configure them from the local web interface of the device. Read the Device Configurations article for more information on how to access it.
When the web interface of the device is opened, navigate to the Setup tab, select Settings, and choose the following configuration: