bigger images in facebook posts when posting via facebook php sdk

Question

I have the following code to generate a facebook post for a page using graph api.

 $page_info = $facebook->api("/$pageId?fields=access_token");
 if (!empty($page_info['access_token'])) {
 $attachment = array(
 'access_token' => $page_info['access_token'],
 'message' => $msg,
 'name' => $title,
 'link' => $uri,
 'description' => $desc,
 'picture'=>$pic,
 'actions' => json_encode(array('name' => $action_name,'link' => $action_link))
 );

$status = $facebook->api("/$pageId/feed", "post", $attachment);

Posts from one of my facebook pages look like below image.

link to image - How my posts look

Then i came across some other pages, whose posts look like below image. As you can see, these preview images are large and appear above the post. When we click them, we are redirected to another website's page. So i had to assume, we are not posting this as image. Please note that i need to post my link, big thumbnail and my custom description as shown in this image.

How to achieve this?

link to image - How my posts should look like

Answer 1

bigger images in facebook posts when posting

Use the Open Graph to create the custom stories.