Show Featured Images in Admin Columns.php

/*** Show Featured Images in admin columns
–––––––––––––––––––––––––––––––––––––––––––––––––– ***/
// Add filters for 'post' post type.
add_filter('manage_posts_columns', 'wsv_add_thumbnail_column', 5);
add_action('manage_posts_custom_column', 'wsv_display_thumbnail_column', 5, 2);

// Add filters for 'page' post type.
add_filter('manage_pages_columns', 'wsv_add_thumbnail_column', 5);
add_action('manage_pages_custom_column', 'wsv_display_thumbnail_column', 5, 2);

// Use the same function for adding thumbnail column for both posts and pages
function wsv_add_thumbnail_column($defaults) {
    $defaults['wsv_post_thumbs'] = __('Featured Image');
    return $defaults;
}

// Use the same function for displaying thumbnail column for both posts and pages
function wsv_display_thumbnail_column($column_name, $id) {
    if($column_name === 'wsv_post_thumbs'){
        echo the_post_thumbnail('thumbnail');
    }
}

// Function to add custom CSS for the thumbnail column
function wsv_custom_featuredimage_css() {
    echo '
        <style type="text/css">
            .column-wsv_post_thumbs img {
                width: 75px !important;
                height: 75px !important;
                overflow: hidden !important;
            }
        </style>
    ';
}

// Hook the custom CSS function into the admin head
add_action('admin_head', 'wsv_custom_featuredimage_css');