x.Family.Name is is the combination of 2 properties (Revit API) Family Property and Name Property (Inherited from [Element ]
Element.Name.GetValue(objet) is a dotnet method PropertyInfo.GetValue Méthode (System.Reflection) | Microsoft Learn to get value from a Property because Dynamo use IronPython
you can also use
Element.Name.__get__(objet)
__get__ — Python Reference (The Right Way) 0.1 documentation
Note: FamilySymbol.Name does not work due to a IronPython limitation
more info here