Display Images with More Fields yes / no

Add a new “more field” radio button. For its value use *Show, Hide. The asterisk defaults to “Show”.

PHP

$value = get_post_meta($post->ID, 'my_image', true);

if ( $value == 'Show' ) {
    echo '<img src="https://wordpress.stackexchange.com/questions/49217/myimage.jpg">';
}