Google seems to have launched a new user interface and layout for the AdWords Sitelinks. Instead of a 2 by 2 format or the card style format, Google is showing some AdWords sitelinks as four linear links directly under the ad.
Here is a screen shot from Kyle Reddoch on Twitter but I am able to replicate it on my iPhone:
I don't think I've ever seen this format out in the wild.
Forum discussion at Twitter.