Google Sitelinks Update?

I happen to see a new format of Google Sitelinks while performing search query this morning.

sitelinks-update

Notice the layout of the links. They occupy less space but they are also aren’t as prominent as in previous layout as shown here.

living-hk-sitelinks

Another query showed a surprising layout. The top ranked didn’t get any sitelink at all, but the site ranked below it has sitelinks using the new format!

Google Sitelink Enhancement?

So far I not yet found an official statement from Google regarding this update.