This shows two Diagrams with separate Models in two separate but completely overlapping HTML DIV elements. This assumes that Diagram 2 is showing a copy of the model of Diagram 1 after some changes.

Show: Diagram 1 Diagram 2 Both Diagrams

You can see differences between the two models by clicking "Show Diff". Nodes or Links added in Diagram 2 are highlighted in yellow. Nodes or Links removed in Diagram 2 are highlighted in red. Modified Nodes or Links are highlighted in cyan.

Current state of Model 1:

Current state of Model 2: