{% load i18n wagtailadmin_tags %}

<li class="icon icon-image">
    <a href="{% url 'wagtailimages:index' %}">
    {% blocktrans count counter=total_images with total_images|intcomma as total %}
        <span>{{ total }}</span> Image
    {% plural %}
        <span>{{ total }}</span> Images
    {% endblocktrans %}
    </a>
</li>