Get smaller size of image, get_the_post_thumbnail

Just change the code to:

$image_output="<div class="x-recent-posts-img">" . get_the_post_thumbnail( get_the_ID(), 'thumbnail', NULL ) . '</div>';

See in the Codex:

Thumbnail Sizes

get_the_post_thumbnail

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