The doorbell built on the door knocker. In turn, the intercom and the surveillance camera built on the doorbell. Each device means something different, and each device means something different in the context of the others. Today, for example, a house with only a knocker says, in effect, “None of that new-fangled technology for us.” A modern door knocker also puts some additional burden on the visitor. A doorbell, by and large, doesn’t show any evidence of the hand that touches it: a heavy or light hand yields the same beep, the same ring, the same chime. A door knocker, in contrast, will sound loud or quiet, firm or tentative, depending on the individual employing it. Likewise, a single light means different things in different contexts. On a doorbell, it is a helpful guide in the dark of night. On a doorbell equipped with a surveillance camera, the light is a reminder that someone is watching. It says “I’m on,” which really means “You’re on film.” As for the intercom, such as this one here, a light is a little peculiar. What does it mean, exactly? This photograph was shot outside a gallery in Manhattan’s Chelsea neighborhood. The light seems to be an invitation. It seems to say, “Click me.” The doorbell suggests itself as the welcoming salvo from an oracle, one that is waiting inside to be asked a question.An ongoing series cross-posted from instagram.com/dsqt.