The url of the site is http://www.metropolitanfashionhub.com. However the plugin picks up http://www.metropolitanfashionhub.com/wp/ (which is the folder where WP is installed) and uses that url to parse to twitter:domain. Which in turn will give a 404 error to anyone who clicks on it.
I didn't see anything in the options to specify the correct URL. For the time being I've modified the plugin files and removed the following line:
echo '<meta property="twitter:domain" content="' . get_bloginfo('wpurl') . '"/>'."\n";
Is there a better way of fixing this?