Google is always testing something. In this case, Google seems to be testing a new design and user interface for Google Images, which users have managed to spot and screenshot. This new interface filter bubbles at the top, which suggests ways to filter your image search. A new preview for the image you selected is also offered.
Rather than showing that image on the normal black background, Google shows the image on a white background on the right side of the page.
Here is a screen shot from @thibaultadda on Twitter:
Here is how it looks now:
Is Google planning on rolling this out, or is this just a limited test, and that’s it? The number of people that shared screenshots of this design online indicates that this is a fairly big test if it is one.