Impossible to invoke a method ("resize") on a null variable.
<img src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" data-src="{{ picture.resize(478).url }}" alt="{{ picture.caption.html|raw }}" class="lazyload grid-image"/>
</picture>
</figure>
{% elseif article_style == 'wider' %}
<figure class="article-item__image article-item__image--desktop">
<picture>
<source media="(min-width: 900px)" data-srcset="{{ picture.resize(598).url }} 1x, {{ picture.resize(1196, null, 40).url }} 2x">
<source data-srcset="{{ picture.focusCrop(588, 460).url }} 1x, {{ picture.focusCrop(1176, 920, null, {'quality': 40}).url }} 2x">
<img src="data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==" data-src="{{ picture.resize(598).url }}" alt="{{ picture.caption.html|raw }}" class="lazyload grid-image"/>
</picture>
</figure>
{% endif %}