A solid green indicator light means either the built-in Nest Cam is turned on or the user is currently in a video call.
Given that the device is facing the wall, it's more likely that the built-in Nest Cam is turned on.
A blinking green light indicates that a member of the household is currently viewing the Nest Cam's live feed.
If you wish to disable the microphone and camera, you can use the physical mic and camera switch located on the back of the device. When this hardware switch is toggled off, both streaming and recording are disabled, and an orange indicator light will appear next to the camera. Refer to this page for more details
