hide poster avatars when only two posts

app/assets/javascripts/discourse/components/topic-map.js.es6

@@ -22,6 +22,8 @@ export default Ember.Component.extend({
     this.set('mapCollapsed', Discourse.Mobile.mobileView || (!this.get('topic.has_summary')));
   },
 
+  showPosterAvatar: Em.computed.gt('topic.posts_count', 2),
+
   toggleMapClass: function() {
     return this.get('mapCollapsed') ? 'fa fa-chevron-down' : 'fa fa-chevron-up';
   }.property('mapCollapsed'),

app/assets/javascripts/discourse/templates/components/topic-map.js.handlebars

@@ -44,9 +44,11 @@
         <h4>{{i18n links_lowercase}}</h4>
       </li>
     {{/if}}
+    {{#if showPosterAvatar}}
       <li {{bind-attr class=":avatars mapCollapsed::hidden"}}>
         {{#grouped-each participant in details.fewParticipants}}{{topic-participant participant=participant}}{{/grouped-each}}
       </li>
+    {{/if}}
   </ul>
 </section>