New metric: hiddenImages

lib/metadata/policies.js

@@ -959,13 +959,22 @@ var policies = {
     },
     "lazyLoadableImagesBelowTheFold": {
         "tool": "phantomas",
-        "label": "Not lazyloaded images",
+        "label": "Below the fold images",
         "message": "<p>This is the number of images displayed below the fold that could be lazy-loaded. This is an excellent way to accelerate the loading time of an heavy page.</p><p>I recommend using <a href=\"https://github.com/vvo/lazyload\" target=\"_blank\">this lazyloader</a>.</p>",
         "isOkThreshold": 1,
         "isBadThreshold": 12,
         "isAbnormalThreshold": 30,
         "hasOffenders": true
     },
+    "hiddenImages": {
+        "tool": "phantomas",
+        "label": "Hidden images",
+        "message": "<p>List of all images that have a display:none property, or one of their parents. These images are loaded by the browser even if they're not visible. You might be able to find a way to lazy-load them, only when they get visible.</p><p>Trackers are an exception, you'd better hide them.</p>",
+        "isOkThreshold": 3,
+        "isBadThreshold": 12,
+        "isAbnormalThreshold": 30,
+        "hasOffenders": true
+    },
     "cachingDisabled": {
         "tool": "phantomas",
         "label": "Caching disabled",

lib/metadata/scoreProfileGeneric.json

@@ -17,7 +17,8 @@
                 "notFound": 3,
                 "multipleRequests": 2,
                 "smallRequests": 1,
-                "lazyLoadableImagesBelowTheFold": 2
+                "lazyLoadableImagesBelowTheFold": 2,
+                "hiddenImages": 1
             }
         },
         "domComplexity": {