Bing Search Results Turn Gray On Hover Over Page Selector

Here is another interesting Microsoft Bing feature in its search results. Hover your mouse cursor over the pagination page selector on the footer of the search results and if you look at the search results above it, they all turn gray.

Frank Sandtmann, a German based SEO consultant, sent this to me but I am able to replicate it. Here is a GIF I made of it in action - note, I did not click on anything, I just moved my mouse cursor:

Why is Bing doing this? Who knows, but it is interesting.

Forum discussion at Twitter.