Update date and enhance example descriptions

Author: abinav2307

articles/cosmos-db/mongodb/vcore/operators/set-expression/$setunion.md

@@ -7,7 +7,7 @@
   ms.service: azure-cosmos-db
   ms.subservice: mongodb-vcore
   ms.topic: language-reference
-  ms.date: 08/03/2025
+  ms.date: 09/04/2025
 ---
 
 # $setUnion
@@ -28,9 +28,9 @@ The `$setUnion` operator returns an array that contains all the unique elements
 | --- | --- |
 | `<array1>, <array2>, ...` | Two or more arrays to combine. Each array is treated as a set, and duplicates are removed from the final result. |
 
-## Example
+## Examples
 
-Let's understand the usage with sample JSON from the `stores` dataset.
+Consider this sample document from the stores collection.
 
 ```json
 {
@@ -141,7 +141,7 @@ Let's understand the usage with sample JSON from the `stores` dataset.
 
 ### Example 1: Combine all product categories
 
-The following example produces a complete list of all of a store's unique product categories. The list includes sales and promotion categories.
+This query retrieves a list of all of a store's unique product categories. The list includes sales and promotion categories.
 
 ```javascript
 db.stores.aggregate([
@@ -166,37 +166,39 @@ db.stores.aggregate([
 ])
 ```
 
-The query returns all the unique categories across all sales and promotions.
+This query returns the following result.
 
 ```json
-{
-  "_id": "26afb024-53c7-4e94-988c-5eede72277d5",
-  "name": "First Up Consultants | Microphone Bazaar - South Lexusland",
-  "salesCategories": [
-    "Lavalier Microphones",
-    "Wireless Microphones"
-  ],
-  "firstPromotionCategories": [
-    "Condenser Microphones",
-    "Dynamic Microphones"
-  ],
-  "secondPromotionCategories": [
-    "Streaming Microphones",
-    "Microphone Stands"
-  ],
-  "thirdPromotionCategories": [
-    "Condenser Microphones",
-    "Microphone Stands"
-  ],
-  "allUniqueCategories": [
-    "Lavalier Microphones",
-    "Wireless Microphones",
-    "Condenser Microphones",
-    "Dynamic Microphones",
-    "Streaming Microphones",
-    "Microphone Stands"
-  ]
-}
+[
+  {
+    "_id": "26afb024-53c7-4e94-988c-5eede72277d5",
+    "name": "First Up Consultants | Microphone Bazaar - South Lexusland",
+    "salesCategories": [
+      "Lavalier Microphones",
+      "Wireless Microphones"
+    ],
+    "firstPromotionCategories": [
+      "Condenser Microphones",
+      "Dynamic Microphones"
+    ],
+    "secondPromotionCategories": [
+      "Streaming Microphones",
+      "Microphone Stands"
+    ],
+    "thirdPromotionCategories": [
+      "Condenser Microphones",
+      "Microphone Stands"
+    ],
+    "allUniqueCategories": [
+      "Lavalier Microphones",
+      "Wireless Microphones",
+      "Condenser Microphones",
+      "Dynamic Microphones",
+      "Streaming Microphones",
+      "Microphone Stands"
+    ]
+  }
+]
 ```
 
 ## Related content