ng-bind-html after camera.getPicture

I'm trying to update the HTML of a div with an image name after my user selects an attachment using navigator.camera.getPicture. I can get the HTML to update normally, but not after the user selects an attachment. What easy thing am I missing?

Div I want to update.

<div ng-bind-html="attachmentName"></div>

Controller

.controller('SubmitTicketCtrl', function($scope, $ionicLoading, $ionicPopup,
    SubmitTicketService) {
$scope.submitData = {};
$scope.attachment;
$scope.attachmentName = 'No attachment selected'; // This works.

$scope.addAttachment = function() {
    navigator.camera.getPicture(onSuccess, onFail, { // This works fine.
        quality: 50,
        destinationType: Camera.DestinationType.FILE_URI,
        sourceType: Camera.PictureSourceType.PHOTOLIBRARY,
        targetWidth: 800,
        targetHeight: 800
    });

    function onSuccess(imageURI) {
        alert(imageURI.substr(imageURI.lastIndexOf('/') + 1)); // I can see the image name in the popup
        $scope.attachmentName = imageURI.substr(imageURI.lastIndexOf('/') + 1); // This doesn't work
        $scope.attachment = imageURI;
    }

    function onFail(message) {
        alert('Failed because: ' + message);
    }
}