DOCS-12144: 4.0-4.0.4 behavior

Author: Kay Kim

source/reference/operator/aggregation/arrayToObject.txt

@@ -56,10 +56,9 @@ Definition
 Behavior
 --------
 
-If the name of a field repeats in the array,
-:expression:`$arrayToObject` uses the first value for that field.
+If the name of a field repeats in the array, the value used depends on
+the driver.
 
-For more information on expressions, see :ref:`aggregation-expressions`.
 
 .. list-table::
    :header-rows: 1
@@ -106,6 +105,11 @@ For more information on expressions, see :ref:`aggregation-expressions`.
 
           { "item" : "123abc" }
 
+       If the name of a field repeats in the array, the value for the
+       repeating field depends on the driver. In the
+       :binary:`~bin.mongo` shell, the first value is used for the
+       repeating field.
+       
 
 Examples
 --------
@@ -142,15 +146,18 @@ document:
 
 The operation returns the following:
 
+.. note::
+
+   If the name of a field repeats in the array, the value for the
+   repeating field depends on the driver. In the :binary:`~bin.mongo`
+   shell, the first value is used for the repeating field.
+
 .. code-block:: javascript
 
    { "_id" : 1, "item" : "ABC1", "dimensions" : { "l" : 25, "w" : 10, "uom" : "cm" } }
    { "_id" : 2, "item" : "ABC2", "dimensions" : { "l" : 50, "w" : 25, "uom" : "cm" } }
    { "_id" : 3, "item" : "ABC3", "dimensions" : { "l" : 50 } }
 
-If the name of a field repeats in the array,
-:expression:`$arrayToObject` uses the first value for that field.
-
 ``$objectToArray`` + ``$arrayToObject`` Example
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~