It&#x27;s more like pinning a photo on a pinboard you share with a group of friends. Mailing it would be like sending it to them directly.<p>I think hashtags are more of a way to share to a group, where as mentioning with @ is a driect way of communicating that you want to give them the picture.<p>This is because hashtags aren&#x27;t owned by anyone, but usernames are.