Do not use fill for project images on detail view.

opentech/public/utils/templates/utils/includes/media_box_icon.html

 {% load wagtailimages_tags %}
-{% image page.icon fill-210x210 as page_icon %}
+{% image page.icon max-210x210 as page_icon %}
 
 {% if page_icon %}
     <div class="media-box__image-container">