It's quite a large work, and seems to concern the pleasures of childhood. On the left, a narrow landscape panel suggests the primordial dark that precedes our birth. It is the longest of the periods described here, but our ignorance makes it seem the smallest.
The next two panels concern childhood, and they are the largest. Both children are faced by empty chairs, which symbolize the inevitable death of their parents.
On the right panel, the sadness of age. Mother and father seem estranged and consigned to separate worlds. She is obviously a member of the Copper Cult, but we do not know how this affects their lives.