oh boy how do i go about explaining this, so basically, i presume it is an iPhone with FaceID, the iPhone's with face ID (iphone 11, iphone x, etc) use infrared dots (from a dot projector) to put the dots on your face (when you try and use faceID), then an infrared camera in the phone looks at these dots on your face to determine the depth and well, ok basically bla bla bla the phone's with faceID use an infrared system to determine your facial features and the depth of your nose, your eyes, etc, and what you are seeing is the infrared dot projector projecting infrared light onto someone's face (or well, trying to, it fires no matter if it sees a face or not), you can also see this effect if you point the remote at the camera, or even (since the iphone's front facing camera doesn't have an ir filter) point something like a remote into the front facing camera of an iphone and you'll see the infrared light (also tbh you can probably see the infrared light using the front facing iphone camera technique to see the dot projector with another iPhone as well) (god i hope this all makes sense, i'm sorry about my grammar btw, i know its really bad in here, i honestly have no defense for it, i just don't feel like going through and fixing it, but i will read this over myself and make sure you can at least understand it) if you want a more detailed explanation as to what this system is and stuff, if you go back to when they announced the iPhone X at the keynote of whatever year it was released, i believe they went into detail about FaceID in there, if you have any other questions feel free to ask and i or someone else would be more than happy to help further