diff --git a/vendor/refinerycms/images/lib/images.rb b/vendor/refinerycms/images/lib/images.rb
index <HASH>..<HASH> 100644
--- a/vendor/refinerycms/images/lib/images.rb
+++ b/vendor/refinerycms/images/lib/images.rb
@@ -22,6 +22,12 @@ module Refinery
         app_images.analyser.register(Dragonfly::Analysis::RMagickAnalyser)
         app_images.analyser.register(Dragonfly::Analysis::FileCommandAnalyser)
 
+        # This little eval makes it so that dragonfly urls work in traditional
+        # situations where the filename and extension are required, e.g. lightbox.
+        # What this does is takes the url that is about to be produced e.g.
+        # /system/images/BAhbB1sHOgZmIiMyMDEwLzA5LzAxL1NTQ19DbGllbnRfQ29uZi5qcGdbCDoGcDoKdGh1bWIiDjk0MngzNjAjYw
+        # and adds the filename onto the end (say the image was 'refinery_is_awesome.jpg')
+        # /system/images/BAhbB1sHOgZmIiMyMDEwLzA5LzAxL1NTQ19DbGllbnRfQ29uZi5qcGdbCDoGcDoKdGh1bWIiDjk0MngzNjAjYw/refinery_is_awesome.jpg
         app_images.instance_eval %{
           def url_for(job, *args)
             image_url = nil
Serious hacks require serious documentation.