а как быть с

foreach($list as & $l){
            $l['image'] = '';
            if(!empty($l['tvs']['image']['value'])){
                $l['image'] = $images_base_url . $l['tvs']['image']['value'];
            }
            else{
                $l['imageDefault'] = $images_base_url . 'products/no_photo.png';
            }
        }