As shown in the flow chart, the idea is when a person / user comes in from of the device, the camera detects face / humans, process the image.
It removes the background and adds a black background, because for projecting an object as hologram it is necessary. Once the image is processed another program replicated the video stream into four different directions which is then viewed on the device. This is taken care by one system.
The other system checks the object for distance and light. An light sensor and a distance sensor is attached to the device. When an object is at a certain range from the device, the systems wakes up the primary system to check for face detection. Also the secondary system checks the amount of light on the object. If the object is illuminated below a certain lux level, it will switch on external light attached to the device.
This is the basic working of the device.