app/views/thredded/posts_common/_header.html.erb
<header>
<%= image_tag post.avatar_url, class: 'thredded--post--avatar' if post.user %>
<h2 class="thredded--post--user"><%= user_link post.user %></h2>
<a href="<%= post.permalink_path %>" rel="nofollow" class="thredded--link thredded--post--created-at right">
<%= time_ago post.created_at %>
</a>
</header>