The document provides steps to modify the content.php file in the Twenty Fourteen child theme. It instructs the user to copy content.php from the parent theme, delete certain code sections marked with red borders, and replace one section with alternative code provided. The code replaces conditionals that output excerpts or full content with code that displays thumbnails and content for home and archive pages.

1. TWENTY FOURTEEN THUMBNAILS
Source: http://youtu.be/oLct6SLTtjc
Complete steps in blog.web6.org

2. STEPS:
1. Copy content.php from Twenty Fourteen parent theme to
the child theme
2. Open content.php in the child theme, and delete the
following code that is red bordered in the picture.

3. 3. Still in the content.php of child theme, delete the following
code red border in the picture and replace it with the code in
next page.

4. 4. The code:
<?php if ( is_search() ) { ?>
<div class="entry-summary">
<?php the_excerpt(); ?>
</div><!-- .entry-summary -->
<?php } elseif ( is_home() ) { ?>
<div class="entry-content">
<?php if ( has_post_thumbnail()) : ?>
<a href="<?php the_permalink(); ?>" title="<?php the_title_attribute(); ?>" >
<?php the_post_thumbnail('thumbnail', array('class' => 'alignleft')); ?>
</a>
<?php endif; ?>
<?php the_content( __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentyfourteen' ) ); ?>
</div><!-- .entry-content -->
<?php } else { ?>
<div class="entry-content">
<?php
the_content( __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentyfourteen' ) );
wp_link_pages( array(
'before' => '<div class="page-links"><span class="page-links-title">' . __( 'Pages:', 'twentyfourteen' ) . '</span>',
'after' => '</div>',
'link_before' => '<span>',
'link_after' => '</span>',
) );
?>
</div><!-- .entry-content -->
<?php } ?>