Repr style out for widgets

IPython/core/formatters.py

@@ -149,6 +149,9 b' class DisplayFormatter(Configurable):'
         format_dict = {}
         md_dict = {}
 
+        # If _ipython_display_ is defined, use that to display this object.  If
+        # it returns NotImplemented, use the _repr_ logic (default).
+        if not hasattr(obj, '_ipython_display_') or obj._ipython_display_(**kwargs) == NotImplemented:
         for format_type, formatter in self.formatters.items():
             if include and format_type not in include:
                 continue