Google experiments with a new feature that previews search results when you mouse over them. Benjamin Rubin, who sent the screenshots, has more information about this feature:

"Starting this morning, I started to get a highlighted-box mouse-over effect along with that magnifying glass icon on most of my search result entries. Clicking on it toggles a preview image with some text highlighted as well. The image preview differs slightly depending on where the aforementioned text appears on the page."

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