Why when I click publish my image is not showing on Facebook?

Question

On my website when I click the Facebook button for share a post, I get a preview with a correct image but once I publish the same picture is not showing inside Facebook.

So I tried to fetch new scrape from the debugger, I don't have any issue related, also below the "When shared, this is what will be included" it shows me the correct image.

EDIT

I don't have a meta tag og:image in the head, because my page has different items, each one with a facebook button. I'm using the TimThumb (ver. 2.8.14) script for the scope.

<div class="song-art"><a href="'.$this->url.'/index.php?a=track&id='.$row['id'].'" property="og:image" rel="loadpage"><img style="width: 112px;" src="'.$this->url.'/thumb.php?src='.$row['art'].'&t=m&w=200&h=200" id="song-art'.$row['id'].'" /></a></div>

This is how it looks the customized part of TimThumb script:

require_once('./includes/config.php');

if(!empty($_GET['t'])) {
    if($_GET['t'] == 'a') {
        $type = 'uploads/avatars';
        $width_list = array(25, 50, 100, 112, 150, 200);
        $height_list = array(25, 50, 100, 112, 150, 200);
        $quality_list = array(50, 75, 100);
    } elseif($_GET['t'] == 'm') {
        $type = 'uploads/media';
        $width_list = array(25, 50, 75, 100, 112, 200, 204, 300, 435, 500, 650, 700, 800, 900, 1000);
        $height_list = array(25, 50, 75, 100, 112, 200, 204, 300, 435, 500, 650, 700, 800, 900, 1000);
        $quality_list = array(50, 75, 100);
    } elseif($_GET['t'] == 'c') {
        $type = 'uploads/covers';
        $width_list = array(300, 800, 900, 1000, 1100, 1200);
        $height_list = array(100, 200, 300);
        $quality_list = array(50, 75, 100);
    } else {
        exit('Invalid parameter value');
    }
} else {
    exit('The \'t\' parameter is not set.');
}

// Build up the src query
$_GET['src'] = $CONF['url'].'/'.$type.'/'.$_GET['src']; 

if(!empty($_GET['w'])) {
    if(!in_array($_GET['w'], $width_list)) {
        exit('Invalid width value.');
    }
}

if(!empty($_GET['h'])) {
    if(!in_array($_GET['h'], $height_list)) {
        exit('Invalid height value.');
    }
}

if(!empty($_GET['q'])) {
    if(!in_array($_GET['q'], $quality_list)) {
        exit('Invalid quality value.');
    }
}

Is there anything wrong with my code?