Pinterest Functions Editing

I have Pinterest Js file and functions for displaying Pinterest directly inside all times on the website. I wish to limit it to images that are displayed only inside posts and not on featured images.

This is the functions code that is linked to Pinterest JS. What do I need to change to limit it to images inside posts only?

add_action( 'wp_enqueue_scripts', 'wpsites_pin_images_script' );

function wpsites_pin_images_script() {
    wp_register_script( 'pin-images',
        get_stylesheet_directory_uri() . '/pin.js',
        false,
        '1.0',
        true
    );

    wp_enqueue_script( 'pin-images' );
}

Pin.js new file

(function(d){
  var f = d.getElementsByTagName('SCRIPT')[0], p = d.createElement('SCRIPT');
  p.type = 'text/javascript';
  p.setAttribute('data-pin-hover', true);
  p.async = true;
  p.src = '//assets.pinterest.com/js/pinit.js';
  f.parentNode.insertBefore(p, f);
}(document));