app/views/reports/_picture_item.erb
<li class="<%= html_class %>" >
<%= f.label :title %>
<%= f.text_field :title %>
<% if !f.object.new_record? %>
<%= image_tag f.object.file.url(:thumb) %>
<%= f.check_box :_destroy %>
<%= f.label :_destroy, 'Remove' %>
<% end %>
<%= f.file_field :file %>
</li>