Icon on top of link instead of left/right

I modified your code so Top was an option. The only change was to add a condition so when Top is selected, background-position is only at top, no left or right.

I didn’t test it on several sites / themes, etc. It works perfectly on mine.

Here’s what I did:

$mtli_leftorright = ( in_array( $mtli_leftorright, array( 'left', 'right', 'top' ) ) ? $mtli_leftorright : 'left' );

echo '
.mtli_attachment {
	display:inline-block;
	height: auto;
	min-height:' . $mtli_height . 'px;
	background-attachment: scroll;
	background-repeat: no-repeat;
	padding-' . $mtli_leftorright . ': ' . ( $mtli_height * 1.2 ) . 'px !important;
	background-position: top ' . ($mtli_leftorright = ($mtli_leftorright = "top") ? "" : $mtli_leftorright) . ';
}';

$this->alignments = array(
				'left'	   => __( 'Left', self::$name ),
				'right'    => __( 'Right', self::$name ),
				'top'      => __( 'Top', self::$name ),
			);

https://wordpress.org/plugins/mimetypes-link-icons/