Incorrect but Working Binding

labels.js

Pharos360.labelsController = SC.ArrayController.create(
/** @scope Pharos360.labels.prototype */ {
       
  // TODO: Add your own code here.
          
}) ;

loggedIn.js

  /*
   * This is the portion of the Ki state that sets up the labels' store.
   */

  enterState: function() {
    /*
     * Normally we'd start talking to the server and setup a callback that would
     * fire when the data was received (or we'd observe the datastore and wait for the
     * data to be available). Since this is just a fixtures DataStore...we won't worry
     * about that currently.
     */
    var coursesStore = Pharos360.store.find(Pharos360.Course);
    var labelsStore = Pharos360.store.find(Pharos360.Label);
    
    if (coursesStore != null && labelsStore != null) {
     
      // Setup the controllers
      Pharos360.coursesController.set('content', coursesStore);
      Pharos360.labelsController.set('content', labelsStore);
      
      // Show the UI
      Pharos360.getPath('mainPage.mainPane').append();
      
    } else {
      console.log('An error occured while attempting to load the course/label information.');
    } 
  },

navigation.js

Pharos360.NavigationView = SC.ScrollView.extend(SC.ContentDisplay, {
  
  testVar: "something", 
      
  displayProperties: ['myTest'],
      
  myTestBinding: 'Pharos360.labelsController.arrangedObjects.length',
// DOESN'T WORK:  myTestBinding: 'Pharos360.labelsController.arrangedObjects',
        
  render: function(context) {
    sc_super();
    console.log('render called');
        
    var data = { sc_view:this };
    var template = SC.TEMPLATES['navigation'];
          
    context.push(template(data));
  },      
          
  update: function(jquery) {
    console.log('event fired...');
          
    var labels_html = "";

    Pharos360.labelsController.forEach(function (label, index) {
          
      labels_html += "<li class='label'>" + label.get('title') + "</li>";
    });   
          
    jquery.find('ul.labels').html(labels_html);
  }   

});