scinote-web/app/views/steps/_form_assets.html.erb

<div class="panel panel-default panel-step-attachment">
  <div class="panel-heading">
    <span class="glyphicon glyphicon-file"></span>
    <%= t("protocols.steps.new.asset_panel_title") %>
    <div class="pull-right">
      <%= ff.remove_nested_fields_link do %>
        <span class="glyphicon glyphicon-remove"></span>
      <% end %>
    </div>
  </div>
  <div class="panel-body">
    <% if ff.object.file.exists? %>
      <% if !(ff.object.file.content_type =~ /^image/).nil? %>
        <%= image_tag ff.object.file.url(:medium) %>
        <br>
        <%= ff.object.file_file_name %>
      <% else %>
        <%= ff.object.file_file_name %>
      <% end %>
    <% else %>
      <%= ff.file_field :file %>
    <% end %>
  </div>
</div>