Avatar im Kommentarfeld anpassen? Wie geht's?

<div class="post-content-container">
<?php
/*-----------------------------------------------------------------------------------*/
/*  Begin processing our comments
/*-----------------------------------------------------------------------------------*/
/*
 * If the current post is protected by a password and
 * the visitor has not yet entered the password we will
 * return early without loading the comments.
 */
if ( post_password_required() ) {
    return;
}
?>
<div class="commentlist_parent">
    <a href="#" id="comment-button">
        <?php echo thb_get_comments_number_str(); ?>
    </a>
<?php if ( have_comments() ) : ?>
        <div class="commentlist_container">
            <ol class="commentlist">
                <?php wp_list_comments(
                    array(
                        'type'          => 'comment',
                        'style'       => 'ol',
                        'short_ping'  => true,
                        'avatar_size' => 45
                    )
                ); ?>
            </ol>
    
            <?php if ( get_comment_pages_count() > 1 && get_option( 'page_comments' ) ) { ?>
                <div class="navigation">
                    <div class="nav-previous"><?php previous_comments_link(); ?></div>
                    <div class="nav-next"><?php next_comments_link(); ?></div>
                </div><!-- .navigation -->
            <?php } ?>
        </div>
    
<?php else : 
    if ( ! comments_open() ) :
?>
    <p class="nocomments"><?php _e("Comments are closed", 'thevoux'); ?></p>
<?php endif; // end ! comments_open() ?>


<?php endif; // end have_comments() ?>


<?php
    // Comment Form
    $commenter = wp_get_current_commenter();
    $req = get_option( 'require_name_email' );
    $aria_req = ( $req ? ' aria-required="true" data-required="true"' : '' );
    
    $defaults = array( 'fields' => apply_filters( 'comment_form_default_fields', array(
    
        'author' => '<div class="row"><div class="small-12 medium-6 columns"><input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . ' placeholder="' . __( 'Name', 'thevoux' ) . '"/></div>',
        
        'email'  => '<div class="small-12 medium-6 columns"><input id="email" name="email" type="text" value="' . esc_attr( $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . ' placeholder="' . __( 'Email', 'thevoux' ) . '" /></div>',
        
        'url'    => '<div class="small-12 columns"><input name="url" size="30" id="url" value="' . esc_attr( $commenter['comment_author_url'] ) . '" type="text" placeholder="' . __( 'Website', 'thevoux' ) . '"/></div></div>' ) ),
        
        'comment_field' => '<div class="row"><div class="small-12 columns"><textarea name="comment" id="comment"' . $aria_req . ' rows="10" cols="58" placeholder="' . __( 'Your Comment', 'thevoux' ) . '"></textarea></div></div>',
        
        'must_log_in' => '<p class="must-log-in">' .  sprintf( __( 'You must be <a href="%s">logged in</a> to post a comment.', 'thevoux' ), wp_login_url( apply_filters( 'the_permalink', get_permalink( ) ) ) ) . '</p>',
        
        'logged_in_as' => '<p class="logged-in-as">' . sprintf( __( 'Logged in as <a href="%1$s">%2$s</a>. <a href="%3$s" title="Log out of this account">Log out?</a>', 'thevoux' ), admin_url( 'profile.php' ), $user_identity, wp_logout_url( apply_filters( 'the_permalink', get_permalink( ) ) ) ) . '</p>',
        
        'comment_notes_before' => '<p class="comment-notes">' . __( 'Your email address will not be published.', 'thevoux' ) . '</p>',
        'comment_notes_after' => '<p class="form-allowed-tags">' . sprintf( __( 'You may use these <abbr title="HyperText Markup Language">HTML</abbr> tags and attributes: %s', 'thevoux' ), ' <code>' . allowed_tags() . '</code>' ) . '</p>',
        'id_form' => 'form-comment',
        'id_submit' => 'submit',
        'title_reply' => __( 'Leave a Reply', 'thevoux' ),
        'title_reply_to' => __( 'Leave a Reply to %s', 'thevoux' ),
        'cancel_reply_link' => __( 'Cancel reply', 'thevoux' ),
        'label_submit' => __( 'Submit Comment', 'thevoux' ),
    ); 
comment_form($defaults); 
?>
    </div>
</div>

<?php


/* Custom GRAvatar */
function thb_gravatar ($avatar_defaults) {
    $myavatar = THB_THEME_ROOT . '/assets/img/avatar.png';
    $avatar_defaults[$myavatar] = 'THB Gravatar';
    return $avatar_defaults;
}
add_filter('avatar_defaults', 'thb_gravatar');


/* Custom Comment Styling */
function thb_enable_threaded_comments(){
    if (!is_admin()) {
        if (is_singular() AND comments_open() AND (get_option('thread_comments') == 1)) {
            wp_enqueue_script('comment-reply');
        }
    }
}
add_action('get_header', 'thb_enable_threaded_comments');




/**
 * Modifies WordPress's built-in comments_popup_link() function to return a string instead of echo comment results
 */
function get_comments_popup_link( $zero = false, $one = false, $more = false, $css_class = '', $none = false ) {
    global $wpcommentspopupfile, $wpcommentsjavascript;
 
    $id = get_the_ID();
 
    if ( false === $zero ) $zero = __( 'No Comments', 'thevoux' );
    if ( false === $one ) $one = __( '1 Comment', 'thevoux' );
    if ( false === $more ) $more = __( '% Comments', 'thevoux' );
    if ( false === $none ) $none = __( 'Comments Off', 'thevoux' );
 
    $number = get_comments_number( $id );
 
    $str = '';
 
    if ( 0 == $number && !comments_open() && !pings_open() ) {
        $str = '<span' . ((!empty($css_class)) ? ' class="' . esc_attr( $css_class ) . '"' : '') . '>' . $none . '</span>';
        return $str;
    }
 
    if ( post_password_required() ) {
        $str = __('Enter your password to view comments.', 'thevoux');
        return $str;
    }
 
    $str = '<a href="';
    if ( $wpcommentsjavascript ) {
        if ( empty( $wpcommentspopupfile ) )
            $home = home_url();
        else
            $home = get_option('siteurl');
        $str .= $home . '/' . $wpcommentspopupfile . '?comments_popup=' . $id;
        $str .= '" onclick="wpopen(this.href); return false"';
    } else { // if comments_popup_script() is not in the template, display simple comment link
        if ( 0 == $number )
            $str .= get_permalink() . '#respond';
        else
            $str .= get_comments_link();
        $str .= '"';
    }
 
    if ( !empty( $css_class ) ) {
        $str .= ' class="'.$css_class.'" ';
    }
    $title = the_title_attribute( array('echo' => 0 ) );
 
    $str .= apply_filters( 'comments_popup_link_attributes', '' );
 
    $str .= ' title="' . esc_attr( sprintf( __('Comment on %s', 'thevoux'), $title ) ) . '">';
    $str .= thb_get_comments_number_str( $zero, $one, $more );
    $str .= '</a>';
     
    return $str;
}
 
/**
 * Modifies WordPress's built-in comments_number() function to return string instead of echo
 */
function thb_get_comments_number_str( $zero = false, $one = false, $more = false, $deprecated = '' ) {
    if ( !empty( $deprecated ) )
        _deprecated_argument( __FUNCTION__, '1.3' );
 
    $number = get_comments_number();
 
    if ( $number > 1 )
        $output = str_replace('%', number_format_i18n($number), ( false === $more ) ? __('% Comments', 'thevoux') : $more);
    elseif ( $number == 0 )
        $output = ( false === $zero ) ? __('No Comments Yet', 'thevoux') : $zero;
    else // must be one
        $output = ( false === $one ) ? __('1 Comment', 'thevoux') : $one;
 
    return apply_filters('comments_number', $output, $number);
}
?>