Emoji
is a new feature added to WordPress 4.2 core and has nothing to do with your WP SEO code. You can remove these by using this removing action in functions.php
Code Update
– Christine Cooper’s answer here: Disable Emojis deals with all Emoji content throughout the site.
function disable_wp_emojicons() {
// all actions related to emojis
remove_action( 'admin_print_styles', 'print_emoji_styles' );
remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
remove_action( 'wp_print_styles', 'print_emoji_styles' );
remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );
// filter to remove TinyMCE emojis
add_filter( 'tiny_mce_plugins', 'disable_emojicons_tinymce' );
}
add_action( 'init', 'disable_wp_emojicons' );
or use this plugin: Disable Emojis