I read a lot about that "trick" of uploading photos before a caption is applied, but I am not quite sure why this gets all of the attention it does. I've been

I read a lot about that "trick" of uploading photos before a caption is applied, but I am not quite sure why this gets all of the attention it does. I've been loading things in the background of my apps for years, and is something I think most programmers would do by default. Could someone explain to me what makes this unique?