[DaFive]

contentLoaderInfo.content.

Добавлено через 5 минут
Вообще в хэлпе пример даже есть по загрузке картинки.

var url:String = "http://www.helpexamples.com/flash/images/image2.jpg";
var urlRequest:URLRequest = new URLRequest(url);
var loader:Loader = new Loader();
loader.contentLoaderInfo.addEventListener(Event.COMPLETE, loader_complete);
loader.load(urlRequest);
addChild(loader);
 
function loader_complete(evt:Event):void {
    var target_mc:Loader = evt.currentTarget.loader as Loader;
    target_mc.x = (stage.stageWidth - target_mc.width) / 2;
    target_mc.y = (stage.stageHeight - target_mc.height) / 2;
}