Going over a bit of what Donny offered, with Gironda's instructions:
Though a great movement, the bar to the neck bench is not meant for everyone (actually no one exercise is). This form of benching should require a alert spotter(s) standing by. Or a set of well placed stops/pins, which can take away the full affect of the exercise, usually not allowing the full stretch that is a part of this type bench. Try to remember that this is not the most joint friendly exercise, so might be using a weight that can be controlled, fully, each rep. It is not designed for heavy weight sessions, as in normal benching. Pretty much about the total stretch.
In any event, a good stretch and warmup would be advised before getting into this serious bench workout. Keeping the elbows out to (or near) a 90 degree position give the most results. Preferred with a wide, to extra wide, grip. As the pictures show, raising the knees up seems to give better focus and less influence from the legs/lower body. And reduced or no back arch. Some BB'ers will even put a heavy towel/pad under the hips, while having the knees raise. This exercise was never designed for any type of cheating, hence the legs raised. Not sure what Gironda meant by "to the neck", but I would suspect where the lower neck meets the shouldesr boney part.
As far as the impressive upper pec's and development goes, that would depend a lot on the genetic structure; muscle inserts, bone leverage/length, direction of muscle influence/force, etc. If you were born with that potential of fully developed upper chest, even flat benches should take care of that.Can always improve any muscle area, but there will be limits compared to other guy's who may have that natural inclination of a great upper pec tie in. Columbo, as a very good example. Good Luck.