Last week Google dropped their instant previews in the Search Engine Results Pages because of low usage. These previews allowed you to see a screenshot of the site before you clicked through and the text you search for would be highlighted. It wasn't a full clear screenshot because you would still need to click-through to read the actual text on the page. It has now been replaced with a new drop down with 3 options
Cached shows you the last cached version of the page, Similar does a related search for the urls and Share only shows when you are logged in to Google Plus and offers to share the url on your Google Plus page.
I did a search for my name "Oral Seymour" also noticed that the Similar link didn't show on my Twitter, Myspace or Quora results.
Here is the quote from Jessica from Google in response to a question in the Google Product forums
As we’ve streamlined the results page, we’ve had to remove certain features, such as Instant Previews. Instant previews saw very low usage by our users, and we’ve decided to focus on streamlining the page to benefit more users.