var object = {method: function(){return this}};
alert([
  (object.method)(), // вернет object
  (object, object.method)() // вернет window
]);

var object = {method: function(){return this}};
alert([
  (object.method)(),
  (object.method)(), object
]);

var p = 'in window';
var o = 
{
  p: 'in object',
  f: function() {
    alert(this);
    return this.p;
  }
};

var f = o.f;
alert([
  (o.f)(),
  (f)(),
  (o.f, o.f)()
]);