Better describe example 25.

Fixes #237.

Author: gkellogg

index.html

@@ -2394,9 +2394,12 @@ <h1>Advanced Concepts</h1>
 
   <p class="changed">Since <code>json-ld-1.1</code>,
     the <a>vocabulary mapping</a> in a <a>local context</a> can be set to the a <a>relative IRI</a>,
-      which is concatenated to any <a>vocabulary mapping</a> in the <a>active context</a>
-      (see <a href="#document-relative-vocabulary-mapping" class="sectionRef"></a>
-      for how this applies if there is no <a>vocabulary mapping</a> in the <a>active context</a>).</p>
+    which is concatenated to any <a>vocabulary mapping</a> in the <a>active context</a>
+    (see <a href="#document-relative-vocabulary-mapping" class="sectionRef"></a>
+    for how this applies if there is no <a>vocabulary mapping</a> in the <a>active context</a>).</p>
+
+  <p class="changed">The following example illustrates the affect of expanding a property using
+    a <a>relative IRI</a>, which is shown in the Expanded (Result) tab below.</p>
 
   <aside class="example ds-selector-tabs"
          title="Using a default vocabulary relative to a previous default vocabulary">