A snippet after every image

Try get_image_tag filter:

add_filter('get_image_tag', function($html, $id, $alt, $title, $align, $size)
{
    return $html . '<div>some piece of code here</div>';
}, 10, 6);

References:

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)