Ivan

$img = array(
    'id' => $productId,
    'file' => $file,
    'name' => basename($file),
    //'media_source' => $this->config['product_source']
);
$response = $this->modx->runProcessor('mgr/gallery/upload', $img, 
    array('processors_path' => MODX_CORE_PATH . 'components/minishop2/processors/'));

if ($response->isError()) {
    $this->modx->log(1, print_r($response->getMessage(), 1));
}