Well, it's one thing to look at someone else's body and be motivated by it. It's something else to compare yourself to it.
Most trainers say that unless you're doing an intense routine like P90X, it generally takes 2-3 years to get to the point where you want to be. That assumes dedication to aerobic exercise, weight lifting and endurance training- the kind of free time that teenagers and college students usually have but people who work full-time usually don't have.
Some of it is the genetic roll of the dice. The guy in the picture is Asian and it seems that a lot of Asian guys do have a body type that doesn't have a lot of body fat in the torso, they shows a lot of definition in the upper body (especially the arms) but they tend to have trouble developing legs.
Similarly, you're going to have areas where you are strong and that develop easily. You'll also have weak areas that you have to really work hard to develop. Although having seen pictures of you, you have a lean mesomorphic body and your lower body develops easily and stays proportionate to your upper body.