gnu-social/plugins/ImageEncoder/templates/imageEncoder/imageEncoderView.html.twig

<figure>
    <img class="u-photo" src="{{ path('attachment_thumbnail', thumbnail_parameters) }}"
         alt="{{ attachment.getFilename() }}">
    <figcaption><a
                href="{{ path('attachment_show', {'id': attachment.getId()}) }}">{{ attachment.getBestTitle(note) }}</a>
    </figcaption>
</figure>