Fatal error com JSON

Boa tarde, esta me retornando esse erro, pode me ajudar?

"Fatal error: Cannot use object of type stdClass as array in C:\xampp\htdocs\teste.php on line 16"

Estrutura do JSON.

"_embedded": {
"product": [
{
"sku": "SQUID7034",
"name": "Sabonete 354ml",
"images": [
{
"filename": "base_Image.jpg"
},
{
"filename": "small_Image.jpg"
}
],
"mainImage": {
"filename": "thumbnail.jpg"
},
},

Minha estrutura PHP.

<?php
ini_set('max_execution_time', 0); ?>
<?php

include 'oauth.php';
include 'products.php';

$thumbnail = json_decode( $response, false );
 foreach ( $thumbnail->_embedded->product as $thumb){
 $thumbnail = $thumb->mainImage;
 echo 'thumbnail__ = ', $thumbnail->filename . '<br>';}

$base_Image = json_decode( $response, false );
 foreach ( $base_Image->_embedded->product as $base){
 $base_Image = $base->mainImage;
 echo 'base_Image = ', $base_Image[0]->filename . '<br>';}

$small_Image = json_decode( $response, false);
 foreach ( $small_Image->_embedded->product as $small){
 $small_Image = $small->mainImage;
 echo 'small_Image = ', $small_Image[1]->filename . '<br>';}

?>