Add viewer notes.

recipe/0032-collection/index.md

@@ -41,6 +41,12 @@ None known.
 
 This example IIIF Collection represents an organization’s collection of paintings by the American painter Winslow Homer, which includes two distinct artworks: _The Gulf Stream_ and _Northeaster_. Each painting is represented within the Collection as a IIIF Manifest, identified by a URI as its `id`, a `type` property, and the corresponding title as the `label`.
 
+Note: Each supporting viewer has a distinct method for toggling between Collection items.
+
+ - Universal Viewer outputs items in an _Index_ tab.
+ - Mirador presents a dialog that allows users to select an item. 
+ - Clover renders items as options in a dropdown element.
+
 **Example Collection**
 
 {% include manifest_links.html viewers="UV, Mirador, Annona, Clover" manifest="collection.json" %}