diff --git a/glue/core/data_collection.py b/glue/core/data_collection.py
index 753b18e74..863a7baa8 100644
--- a/glue/core/data_collection.py
+++ b/glue/core/data_collection.py
@@ -424,7 +424,7 @@ def __setitem__(self, key, data):
         if not isinstance(key, str):
             raise TypeError("item key should be a string, but got {0}".format(type(key)))
 
-        if not isinstance(data, Data):
+        if not isinstance(data, BaseCartesianData):
 
             handler, preferred = data_translator.get_handler_for(data)
 
diff --git a/glue/viewers/common/viewer.py b/glue/viewers/common/viewer.py
index 86bee0391..abf48320a 100644
--- a/glue/viewers/common/viewer.py
+++ b/glue/viewers/common/viewer.py
@@ -39,12 +39,14 @@ class BaseViewer(HubListener):
     The base class for all viewers.
     """
 
-    LABEL = 'Override this'
+    LABEL = None
 
     def __init__(self, session):
         self._session = session
         self._data = session.data_collection
         self._hub = None
+        if self.LABEL is None:
+            self.LABEL = str(self.__class__)
 
     def register_to_hub(self, hub):
         self._hub = hub
diff --git a/glue/viewers/image/state.py b/glue/viewers/image/state.py
index 762676aa0..0c6ae51b3 100644
--- a/glue/viewers/image/state.py
+++ b/glue/viewers/image/state.py
@@ -149,11 +149,11 @@ def reset_limits(self):
     def _display_world(self):
         return getattr(self.reference_data, 'coords', None) is not None
 
-    def _reference_data_changed(self, *args):
+    def _reference_data_changed(self, *args, force=False):
         # This signal can get emitted if just the choices but not the actual
         # reference data change, so we check here that the reference data has
         # actually changed
-        if self.reference_data is not getattr(self, '_last_reference_data', None):
+        if self.reference_data is not getattr(self, '_last_reference_data', None) or force:
             self._last_reference_data = self.reference_data
             # Note that we deliberately use nested delay_callback here, because
             # we want to make sure that x_att_world and y_att_world both get
diff --git a/glue/viewers/image/viewer.py b/glue/viewers/image/viewer.py
index c4ffb3b0f..142cd09ef 100644
--- a/glue/viewers/image/viewer.py
+++ b/glue/viewers/image/viewer.py
@@ -86,6 +86,10 @@ def add_data(self, data):
             self._set_wcs()
         return result
 
+    def _update_data(self, *args, **kwargs):
+        super()._update_data(*args, **kwargs)
+        self.state._reference_data_changed(force=True)
+
     def _on_slice_change(self, event=None):
         if self._changing_slice_requires_wcs_update:
             self._set_wcs(relim=False)