Why Javascript Singleton is written like this?

Everywhere I saw an implementation of singleton in javascript in a such manner:

var Singleton = (function () {
    var instance;

    function createInstance() {
        var object = new Object("I am the instance");
        return object;
    }

    return {
        getInstance: function () {
            if (!instance) {
                instance = createInstance();
            }
            return instance;
        }
    };
})();

Here we can see that it returns a function which we must call in order to get an object. Question: Why we can't just write like this:

var Singleton = (function () {

    function privateMethod() {
        ...
    }

    return {
        publicMethod1: function() { },
        publicMethod2: function() { },
    };
})();

Somebody will say that reason is for inheritance support. However, I don't see a difference. Anyway Singleton is an object now.