Click on the blue arrow button takes you to the advertiser site; click anywhere else and you need to confirm your request
Google's research found most accidental click-throughs happen at the outer edge of the ad when you are trying to click on or scroll to nearby content. A few years ago, Google tested "confirmed clicks" with text ad banners on smartphones. In those cases, clicking on a blue arrow took you directly to the advertiser's site while a click elsewhere on the banner forced you to confirm your intention. Google has now added this to in-app image banners and found that the confirmed clicks system let to a slight improvement in mobile conversion rates with a slight drop in click-through rates as accidental clicks were eliminated.
Google feels that by solving what is known as the "fat finger" problem with the "confirmed clicks," Google is helping "users, advertisers, publishers, and the mobile ecosystem overall." It might not seem like a big deal, but when you are in a rush to get to a specific page and you end up at an advertiser's site, it can be pretty frustrating.
source: Google via GSMArena