Why do certain tribes leave broken pottery on graves in a specific spot?

Certain tribes leave broken pottery on graves as a symbolic gesture of remembrance and respect for the deceased. This practice may serve to honor the individual's life and ensure their spirit is accompanied by offerings in the afterlife. The specific placement of the pottery can also reflect cultural beliefs about the connection between the living and the dead, as well as the importance of the items in the deceased's life. Overall, it highlights the tribe's traditions and the significance of continuity in their cultural practices.