Children props tip tweak

tips/07-children-props-type.md

@@ -7,7 +7,7 @@ prev: style-props-value-px.html
 next: controlled-input-null-value.html
 ---
 
-Usually, a component's `this.props.children` is an array of components:
+Usually, a component's children (`this.props.children`) is an array of components:
 
 ```js
 /** @jsx React.DOM */
@@ -27,14 +27,16 @@ React.renderComponent(
 );
 ```
 
-To save an extra array allocation, it returns the component itself _without the array wrapper_ when there's only one child.
+However, when there is only a single child, `this.props.children` will be the single child component itself _without the array wrapper_. This saves an array allocation.
 
 ```js
 /** @jsx React.DOM */
 
 var GenericWrapper = React.createClass({
   componentDidMount: function() {
-    // **warning**: yields 5 for length of the string 'hello', not 1 for the
+    console.log(Array.isArray(this.props.children)); // => false
+
+    // warning: yields 5 for length of the string 'hello', not 1 for the
     // length of the non-existant array wrapper!
     console.log(this.props.children.length);
   },