Quick answer: The ER diagram draws the entities and their foreign keys, and the node state reflects the reconciliation status, so a reviewer can see the missing, drift, matched, and extra tables at a glance and trace the relationships behind an API operation. It is a visual map of the same four-layer reconciliation rather than a separate model.

Why the diagram helps the review

A table of statuses and diffs is accurate but slow to read, especially when the model has many relationships. The diagram shows the entities and how they connect, and the node state carries the comparison, so the eye can move from the changed table to its neighbors rather than cross-reference a list.

This keeps the review focused on the structure and the blast radius rather than on assembling the relationships by hand.

What the diagram shows

Element How it appears

Entity A node carrying the table

Foreign key A link between nodes

Link table A node connecting two entities

Node state Color or state reflecting the table…