Referencing property by object.object.name instead of name is 6 times slower

import QtQuick 2.4

Item {
    id: root
    width: 400
    height: 400
    property alias moo: item


    Item {
        id: item
        readonly property bool result: true

        Component.onCompleted: {
            var start, i;
            var iters = 1000000;

            start = new Date;
            i = iters;
            do {
                if (root.moo.result) {
                }
            } while (--i);
            console.log('root.moo.result', new Date - start, root.moo.result);

            start = new Date;
            i = iters;
            do {
                if (result) {
                }
            } while (--i);
            console.log('result', new Date - start, result);
        }
    }
}

qml: root.moo.result 318 true
qml: result 55 true

Why is the second iteration six times slower?