Funny, I was just working on the same issue today on a Inline image upload formset, I ended up with this implementation:
class ImageModelForm(forms.ModelForm):
class Meta:
model = ImageModel
def __init__(self, *args, **kwargs):
super(ImageModelForm, self).__init__(*args, **kwargs)
self.helper = FormHelper(self)
self.helper.form_tag = False
self.helper.disable_csrf = True
self.helper.layout = Layout(
'title',
'description',
'imagefile',
HTML("""{% if form.imagefile.value %}<img class="img-responsive" src="{{ MEDIA_URL }}{{ form.imagefile.value }}">{% endif %}""", ),
'flag_featured',
)