Google now stop showing the instant preview in google searches. One of the spokeman in google told that “We are certainly making alterations to the layout and characteristics of the seek results page”.
But why they eliminate Instant Previews?? Here is the real reason to eliminate the instant previews, most of the searchers are not using the instant preview feature.
Google’s Jessica from the forums said:
As we have efficient the result page, we had to remove certain features, such as instant previews.
Instant preview terribly low usage by our users, and we have determined to specialize on streamlining the result page to gain the users.
Source: http://searchengineland.com/google-we-removed-instant-previews-over-low-usage-from-searchers-156865