Narrow shoulders = never aesthetic He has extremely narrow clavicles and looks a reasonable amount of mass on his shoulders. If he wants to look pretty wide(22-23inches) he will have to put on a considerable amount of mass on his delts, currently he looks around 14-15 inches wide
Here are 5 exercises specific to the shoulders. While genetics does play a role, these exercises may help broaden the look of your shoulders:- Overhead Press (or Military Press) Lateral Raises Front Raises Reverse Flyes. Upright Rows Checkout our body muscle map for other ideas about exercising and building your shoulders:- https://www.realmuscleforum.com/content/choose-which-muscles-to-exercise