[css-shapes-2] improve overflow explanation

Author: astearns

css-shapes-2/Overview.bs

@@ -333,7 +333,10 @@ The 'shape-inside' Property</h4>
 	the exclusion area(s) added
 	by 'shape-inside' and 'shape-padding'
 	(as well as any other exclusion areas
-	in the element's wrapping context).</p>
+	in the element's wrapping context).
+	In other words, 
+	overflow continues outside 
+	the rectangular bounds of the element.</p>
 
 	<div class='figure'>
 		<img alt="Overflow interacting with rounded rect"
@@ -348,6 +351,9 @@ The 'shape-inside' Property</h4>
 		</p>
 	</div>
 
+	Issue: improve the illustration above, 
+	using text to show overflow instead of greeked boxes.
+
 	When a shape-inside has a definite size
 	(no percentages used in the shape's definition)
 	an auto-sized element should use the shape