new_contents: from django.forms.widgets import ClearableFileInput
  from django.utils.safestring import mark_safe
  from django.utils.html import escape
  
  class ImageClearableFileInput(ClearableFileInput):
      template_with_initial = u'%(clear_template)s<br />%(input_text)s: %(input)s'
  
      def img_id(self, name):
          return name + "_img_id"
  
      def render(self, name, value, attrs=None):
          html = super(ImageClearableFileInput, self).render(name, value, attrs)
          img = u'<img id="%s" src="%s"/>' % (self.img_id(name), escape(value.url))
          html = img + html
          return mark_safe(html)
  
subject: add easy_thumbnails/widgets.py add class easy_thumbnails.widgets.ImageClearableFileInput user <img> to replace <a> for current file.