Use higher-res outfit thumbnails if the device has at least 2x DPI

app/helpers/outfits_helper.rb

@@ -48,6 +48,13 @@ module OutfitsHelper
     content_tag :li, :class => class_name, &block
   end
 
+  def outfit_image_tag(outfit)
+    image_tag(
+      outfit.image.small.url,
+      srcset: [[outfit.image.medium.url, "2x"]],
+    )
+  end
+
   def pet_attribute_select(name, collection, value=nil)
     options = options_from_collection_for_select(collection, :id, :human_name, value)
     select_tag name, options, id: nil, class: name

app/views/outfits/_outfit.html.haml

@@ -1,6 +1,6 @@
 = outfit_li_for(outfit) do
   - if outfit.image?
-    = link_to image_tag(outfit.image.small.url), outfit
+    = link_to outfit_image_tag(outfit), outfit
   
   %header
     .outfit-star