[css-display-3][editorial] More wording tweaking. w3c#6123

Author: tabatkins

css-display-3/Overview.bs

@@ -1132,8 +1132,9 @@ Invisibility: the 'visibility' property</h2>
 
 	Note: Currently, many user agents and/or accessibility tools
 	don't correctly implement the accessibility implications of
-	visible elements contained within [=invisible=] elements,
-	so making parent elements with special roles (such as table rows) [=invisible=]
+	visible elements with semantic relationships to [=invisible=] elements,
+	so, for example,
+	making parent elements with special roles (such as table rows) [=invisible=]
 	while leaving child elements with special roles (such as table cells) visible
 	can be problematic for users of those tools.
 	Authors should avoid creating these situations