The Picture Entity card has a show_state option that shows a value in the footer. For all my cameras (which come from BlueIris) it always shows “Idle.” I do have BlueIris communicating to HA via MQTT to control separate binary sensors for each camera indicating detected motion. I gather if I use the binary sensor as the entity for the Picture Entity card and set camera_image to the camera entity it will show the motion detected state, but clicking on the image brings up the binary sensor details rather than the expanded camera view.
However, more useful for me would be to display the time of the last motion detection where the “state” is displayed for a camera. Can I set a camera’s state to an arbitrary string with a timestamp to do this?