Hi David,
do you mean that specific case ({{X,X,Y},{X,Z,V}} -> {{V,V,W},{W,V,Y},{Z,Y,W}}) or a rule in general?
Have you taken a look at this book, where most of the subject is explained in details: https://www.wolframphysics.org/technical-introduction/basic-form-of-models/first-example-of-a-rule/
Then to see, how that particular rule works in Wolfram Models, you can run the next code snippets in your Wolfram App:
rule={{X,X,Y},{X,Z,V}} -> {{V,V,W},{W,V,Y},{Z,Y,W}};
RulePlot[rule]
And:
Dataset[{ResourceFunction["WolframModelPlot"][#], ToString@#} &/@ResourceFunction["WolframModel"][rule,Automatic, 10, "StatesList"]]
Experiment more with the help of the documentation: https://resources.wolframcloud.com/FunctionRepository/resources/WolframModel
And tell us what did you learn.
All the best,
-Marko