Override a views visibility at design time using the tools namespace. See line 13 how and don't forget to add line 2. See http://tools.android.com/tips/layout-designtime-attributes for details.

tools_override.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="vertical">

  <ImageView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@+id/group_image"
      android:src="@drawable/ic_folder"
      android:visibility="gone"
      tools:visibility="visible"
      android:contentDescription="@null" />
</LinearLayout>