Bing seems to be running a new test on their first SERPs: besides blue boxes for sitelinks of the organic number one result, they were showing 2 grey boxes for some other results in the left column.
Possibly these boxes represent entities and main keywords of these pages.
At first glance I don´t see the advantage for regular users. So, maybe this is giving a glimpse into how Bing organizes results? Maybe it's not meant for the public?
