This is done by the "Gallery Grid" Shortcode when you select "classic" Grid layout!
RT @CreativeBloq: Feeling cooped up this winter? Try this pro advice for working from home. https://t.co/zCtax2BCwL Tweet URL
RT @SiteGround: Going home now but see you next time #WCAth2017, such a wonderful experience with so many positive people. Keep on smiling… Tweet URL
RT @Seravo: Back in a snowy Finland after a weekend in these views. Thank you again @WordCampAthens from the conference and greetings from… Tweet URL