The Mystery of the V-Neck Tee, Milano

Why is it that some guys look so cool in a V-neck tee, such as Milan V. in this photo, and some guys look like total sleazeballs?

Usually a good chest helps to fill out a tee, but with a V-neck I think a well defined collarbone is a huge help. This is similar to the idea of never wearing a tank-top unless you have well defined shoulders.