{% load wagtailimages_tags %}
{# Generate responsive image using wagtail image template tag #}
{# Expects Image as img; sizes per design spec #}
{# Adapted from mep-django #}
{% image img max-280x200 as mobile_1x %}
{% image img max-400x300 as desktop_1x %}
<img srcset="{{ mobile_1x.url }} {{ mobile_1x.width }}w,
    {{ desktop_1x.url }} {{ desktop_1x.width }}w"
    sizes="(max-width: 320px) {{ mobile_1x.width }}px,
    {{ desktop_1x.width }}px"
    src="{{ desktop_1x.url }}"
    class="{% if img.width >= img.height %}landscape{% else %}portrait{% endif %}"
    alt="{% firstof alt_text desktop_1x.alt %}" title="{{ desktop_1x.alt }}"
/>