WordPress/wp-content/themes/twentyeleven/content-gallery.php

<?php
/**
 * The template for displaying posts in the Gallery Post Format on index and archive pages
 *
 * Learn more: http://codex.wordpress.org/Post_Formats
 *
 * @package WordPress
 * @subpackage Twenty Eleven
 * @since Twenty Eleven 1.0
 */
?>

<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
	<header class="entry-header">
		<hgroup>
			<h1 class="entry-title"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'twentyeleven' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h1>
			<h2 class="entry-format"><?php _e( 'Gallery', 'twentyeleven' ); ?></h2>
		</hgroup>

		<div class="entry-meta">
			<?php
				printf( __( '<span class="sep">Posted on </span><a href="%1$s" rel="bookmark"><time class="entry-date" datetime="%2$s" pubdate>%3$s</time></a> <span class="sep"> by </span> <span class="author vcard"><a class="url fn n" href="%4$s" title="%5$s">%6$s</a></span>', 'twentyeleven' ),
					get_permalink(),
					get_the_date( 'c' ),
					get_the_date(),
					get_author_posts_url( get_the_author_meta( 'ID' ) ),
					sprintf( esc_attr__( 'View all posts by %s', 'twentyeleven' ), get_the_author() ),
					get_the_author()
				);
			?>
		</div><!-- .entry-meta -->
	</header><!-- .entry-header -->

	<?php if ( is_search() ) : // Only display Excerpts for search pages ?>
	<div class="entry-summary">
		<?php the_excerpt(); ?>
	</div><!-- .entry-summary -->
	<?php else : ?>
	<div class="entry-content">
		<?php if ( post_password_required() ) : ?>
			<?php the_content( __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentyeleven' ) ); ?>

			<?php else : ?>
				<?php
					$images = get_children( array( 'post_parent' => $post->ID, 'post_type' => 'attachment', 'post_mime_type' => 'image', 'orderby' => 'menu_order', 'order' => 'ASC', 'numberposts' => 999 ) );
					if ( $images ) :
						$total_images = count( $images );
						$image = array_shift( $images );
						$image_img_tag = wp_get_attachment_image( $image->ID, 'thumbnail' );
				?>

				<figure class="gallery-thumb">
					<a href="<?php the_permalink(); ?>"><?php echo $image_img_tag; ?></a>
				</figure><!-- .gallery-thumb -->

				<p><em><?php printf( _n( 'This gallery contains <a %1$s>%2$s photo</a>.', 'This gallery contains <a %1$s>%2$s photos</a>.', $total_images, 'twentyeleven' ),
						'href="' . get_permalink() . '" title="' . sprintf( esc_attr__( 'Permalink to %s', 'twentyeleven' ), the_title_attribute( 'echo=0' ) ) . '" rel="bookmark"',
						number_format_i18n( $total_images )
					); ?></em></p>
			<?php endif; ?>
			<?php the_excerpt(); ?>
		<?php endif; ?>
		<?php wp_link_pages( array( 'before' => '<div class="page-link">' . __( 'Pages:', 'twentyeleven' ), 'after' => '</div>' ) ); ?>
	</div><!-- .entry-content -->
	<?php endif; ?>

	<footer class="entry-meta">
		<span class="cat-links"><span class="entry-utility-prep entry-utility-prep-cat-links"><?php _e( 'Posted in', 'twentyeleven' ); ?></span> <?php the_category( ', ' ); ?></span>
		<?php the_tags( '<span class="sep"> | </span> <span class="tag-links"><span class="entry-utility-prep entry-utility-prep-tag-links">' . __( 'Tagged', 'twentyeleven' ) . '</span> ', ', ', '</span>' ); ?>

		<?php if ( comments_open() ) : ?>
		<span class="sep"> | </span>
		<span class="comments-link"><?php comments_popup_link( __( '<span class="leave-reply">Leave a reply</span>', 'twentyeleven' ), __( '<b>1</b> Reply', 'twentyeleven' ), __( '<b>%</b> Replies', 'twentyeleven' ) ); ?></span>
		<?php endif; ?>

		<?php edit_post_link( __( 'Edit', 'twentyeleven' ), '<span class="edit-link">', '</span>' ); ?>
	</footer><!-- #entry-meta -->
</article><!-- #post-<?php the_ID(); ?> -->