Hi Helen, thanks for your interest in our product. Since the Greeter Digital Doorbell & Door Viewer does not have a motion sensor (PIR), it will not take a photo of everyone coming to the door. They have to press the doorbell as a trigger to take photos. Our other product, VEIU Smart Video Doorbell, has the motion sensor feature. Please feel free to take a look on our Houzz page, and let us know if you have other questions. Thank you!