In January, 2014, Google had introduced pop-ups along with Knowledge Graph information about certain websites in their SERPs. Now, it seems like the pop-ups are being tested in the advertisements.
Ariana Wolf, working as a search strategist at 90octane, spotted Knowledge Graph pop-ups appearing on the advertisements for some searches regarding real estate. She, reportedly, said that she found them appearing in case of quite a few searches. She saw that the results were only displayed on the top ad spots, not in the right sidebar, and also that they were fetched from Wikipedia, like, in case of their organic counterparts.
The pop-ups appear when someone clicks on the grey link for the web-master. What's bothering about these pop-ups is that they are snatching traffic from the web masters, via links to Google+ and Wikipedia, which are linked to the logo thumbnail that is shown in every window. The fact that the pop-ups are being examined in advertisements indicates that traffic funnelling to Wikipedia is insubstantial.
Google has said that Knowledge Box shows up in SERPs when a certain website is widely recognised on the web, or when there is enough information or when the content can be very useful for the user.