Visual Search Suggestions are suggestions which include an image and additional text. These can help you visualize what you are searching for and sometimes even get you the information you need without even leaving the search box.
Search Suggestions allow your installed search providers to suggest different queries to you while you are typing. This is great when you aren’t sure of how to spell someone’s name or you can’t quite remember if the movie was called “The Birdcage” or “The Bird’s Nest”. You might already be familiar with textual search suggestions as they are already in use on some popular websites and in some toolbars. (IE8 supports JSON suggestions which some of these use.)
In IE8, we expanded the notion of a suggestion. In addition to providing text suggestions, search providers can now deliver visual suggestions, suggestions which include an image.
Check out this blog post by Jon Box, where he walks you thru the finer points of Search Provider Construction and Discovery.