In the shortiest way, the girl and the boy were breaking up and they still live their lives, they sometimes check each other instagrams (the mv also tells us their happy past) and in the end, they meet again when the boy is going to go for a date (he's hiding roses), that is the time the girl knows she has to move on so she throws all their pictures away, the boy sees she is living happily through a photo in instagram, he smiles and clicks like because he knows she's alright now without him
I'm not sure I'm right or not .