In first div Your Name is: {{Name}} display as it because ng-non-bindable does not compile the data.In second div it compile the {{Name}} which is intializewith FirstName and SecondName.
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.2/angular.min.js"></script>
</head>
<body ng-app>
<div>
<div ng-init="Name='FirstName, LastName'" ng-non-bindable>
Your Name is: {{Name}}
</div>
<div ng-init="Name='FirstName, LastName'">
Your Name is: {{Name}}
</div>
</div>
</body>
</html>