Why is this an issue?

When an anonymous type’s properties are copied from properties or variables with the same names, it yields cleaner code to omit the new type’s property name and the assignment operator.

Noncompliant code example

var X = 5;

var anon = new
{
  X = X, //Noncompliant, the new object would have the same property without the "X =" part.
  Y = "my string"
};

Compliant solution

var X = 5;

var anon = new
{
  X,
  Y = "my string"
};