"Interpersonal" relationships are everywhere - most obviously in chairs, which stand in for the people who sat or will sit in them. Some scenarios immediately make you see inanimate objects as participants in a drama, ie as (human) actors.
Here, the traffic lights seem to me to become "people" - are they a couple ignoring each other while the "slain" light tries to rise up again - or is about to sink down for the last time, despite the protection on offer. Or, is the couple keeping a lookout? And what about the "Green Man" on the other side of the street?