Two phenomena come together, when young people use opportunities to take selfies with Francis: the popularity and playfulness of the selfie itself, the playfulness and the popularity of Pope Francis.
The Holy Father seems delighted in this video. I know that it delights me when young people make a point of saying hello to me in public, unabashedly calling out to me as “Father,” and introducing their friends to me and me to their friends, “This is my priest.” Many of them I do not recognize from being in Mass on Sundays, BUT the fact that they feel comfortable and even proud to approach the local Catholic priest is a blessing to them and to me. It is a holy connection and a holy communion.
With Open Doors 
Abuna, Father, you bring Christ to us. You make us comfortable in our faith family. You model the path for us. You are the teacher. We are gladly your students. We can be more open because you show us how! Remember the lesson of my non catholic friend. He saw true Christianity in you.