A few days ago former US president Barack Obama tweeted  this photo as his response to the awful events in Charlottesville. Twitter has announced that Saturday's tweet is the most-liked tweet ever, so far reaching over 4.1m likes and 1.5m retweets. 

Photographer Pete Souza took the photo in 2011 at a daycare facility next to Mr Obama’s daughter Sasha's school in Bethesda, Maryland. As he was leaving he noticed some small kiddies peering out of the window at the nursery next to his daughter's school so he walked over to say hello.

The photo itself tells a story, and in his tweet Obama paired it with a beautiful Mandela’s quote: