article: author – facebook

Hi,
I have a problem for to show the author on Facebook.
I followed exactly every step for enable it and on the site you see the correct meta tags (this is the site: http://www.executivesummary.it):

<Meta property = “article: author” content = “https://www.facebook.com/nome”&gt;

Unfortunately when I share the post (I use the plugin Easy Social Share Buttons) I do not see the author. Depends on what?
Thank you

https://wordpress.org/plugins/wordpress-seo/