Based on pre-fall studies of primitive tribes, this is a ritual of some kind that took place a while ago.
Looking at the site itself, the effigy is to someone or something, but it has an uncanny resemblance to Death.
The desiccated remains of old flesh hang from the effigy as some sort of symbolic self-sacrifice or commitment.
The vial of blood hanging from the head of the effigy is the focus for this ritual, probably the blood of somebody marked for death as they wronged those that conducted this bizarre ritual.
The word Nemesis comes to mind.