change logo on shop page in canvas

functions.php

function woo_logo () {
	$settings = woo_get_dynamic_values( array( 'logo' => '' ) );
	// Setup the tag to be used for the header area (`h1` on the front page and `span` on all others).
	$heading_tag = 'span';
	if ( is_home() || is_front_page() ) { $heading_tag = 'h1'; }

	// Get our website's name, description and URL. We use them several times below so lets get them once.
	$site_title = get_bloginfo( 'name' );
	$site_url = home_url( '/' );
	$site_description = get_bloginfo( 'description' );
?>
<div id="logo">
<?php
	// Website heading/logo and description text.
	if ( ( '' != $settings['logo'] ) ) {
		$logo_url = $settings['logo'];
                if( is_shop() ){
                    $logo_url = 'i.perezhilton.com/wp-content/uploads/2013/12/zach-galifianakis-santa-claus-comedy-bang-bang.gif';
                }
		if ( is_ssl() ) $logo_url = str_replace( 'http://', 'https://', $logo_url );

		echo '<a href="' . esc_url( $site_url ) . '" title="' . esc_attr( $site_description ) . '"><img src="' . esc_url( $logo_url ) . '" alt="' . esc_attr( $site_title ) . '" /></a>' . "\n";
	} // End IF Statement

	echo '<' . $heading_tag . ' class="site-title"><a href="' . esc_url( $site_url ) . '">' . $site_title . '</a></' . $heading_tag . '>' . "\n";
	if ( $site_description ) { echo '<span class="site-description">' . $site_description . '</span>' . "\n"; }
?>
</div>
<?php
} // End woo_logo()