Как правильно переделать строку?

namespace Application\Controller;

use Zend\Mvc\Controller\AbstractActionController;
use Zend\View\Model\ViewModel;



class IndexController extends AbstractActionController
{
    /**
     * Traits.
     */
    use \Fork\Zend\ServiceManager\Traits\ServiceManagerAwareTrait;
    use \Application\Service\Traits\AsutpServiceAwareTrait;
    use \Application\Service\Traits\MenuServiceAwareTrait;
    use \Application\Service\Traits\FotoServiceAwareTrait;


    public function indexAction()
    {
        $menu = $this->getMenuService()->getMenu();
        $viewModel = new ViewModel(['menu'  => $menu]);
        return $viewModel;
    }

    public function asutpAction()
    {
        $menuId = $this->params()->fromRoute('id', -1);
        $foto = $this->getAsutpService()->getFotoByParentId($menuId);
        $menu = $this->getMenuService()->getMenu();
        $files = $this->getFotoService()->getSavedFiles();
      /**$debugObject = $foto;
// $debugObject = array_keys($debugObject);
        if (is_object($debugObject)) {
            \Zend\Debug\Debug::dump(get_class_vars(get_class($debugObject)) + get_class_methods($debugObject), '<p style="color:blue">' . get_class($debugObject) . '</p>');
        }
        else {
            \Zend\Debug\Debug::dump($debugObject);
        }*/
        $viewModel = new ViewModel(['foto'      => $foto,
                                    'menu'      => $menu,
                                    'files'     => $files]);

        return $viewModel;
    }

$thumb = [];

    foreach ($foto as $f)
    {
        $thumb[] = $f;
    }
    $this->miniFoto()->setThumb($thumb, $files);
    echo $this->miniFoto()->render();

namespace Application\View\Helper;

use Zend\View\Helper\AbstractHelper;


class Thumb extends AbstractHelper
{
    /**
     * Menu thumb array.
     * @var array
     */
    protected $thumb;

    protected $files;

    /**
     * Constructor.
     * @param array $thumb Thumb thumb.
     */
    public function __construct($thumb=[], $files=[])
    {
        $this->thumb = $thumb;
        $this->files = $files;
    }

    /**
     * Sets thumb thumb.
     * @param array $thumb Thumb thumb.
     */
    public function setThumb($thumb)
    {
        $this->thumb = $thumb;

    }

    public function render()
    {
        if (count($this->thumb)==0)
            return ''; // Do nothing if there are no items.

        $result = '<div class="col-2">';
        $result .= '<div class="row">';
        $result .= '<div class="col">';
        $result .= '<p class="text-center">Примеры реализованных проектов</p>';
        $result .= '</div>';
        $result .= '</div>';

        // Визуализация элементов

            foreach ($this->thumb as $item)
            {
                if (preg_match('/[a-z][0-9]+\.[png]+/i', $item['image'] ))
                {
                    $result .= $this->renderItem($item);
                }
            }

        $result .= '</div>';

        return $result;
    }

    protected function renderItem($item)
    {
        $image = isset($item['image']) ? $item['image'] : '';
        $foto = '';
        foreach ($this->files as $file)
        {
            if ($image == $file)
            {
                $foto = $file;
            }
        }
var_dump($foto);
        $result = '';

        $escapeHtml = $this->getView()->plugin('escapeHtml');

        $result .= '<div class="row">';
        $result .= '<div class="col mb-1">';
        $result .= '<img src="'.('application', ['action'=>'file'],
                                ['query'=>['name'=>$escapeHtml($foto)],  'thumbnail'=>true]).'" alt="" class="d-block w-100" data-toggle="modal" data-target="#exampleModal">';
        $result .= '</div>';
        $result .= '</div>';


        return $result;
    }
}