yeh, typically with being on gear you can see it in the shoulders traps, arms......and also back, and chest (well except for legs, i just named pretty much every muscle)
people say shoulders and arms..........cause thats what joe gymrat works out hard.......his chest and arms (shoulders work with chest)
in reality, EVERYTHING should blow up on roids.............my body isnt the biggest, and i am tall...........but i make it a point to really do like arnold say in pump iron........look at the whole body like a sculpter, and bring up lagging parts.........so the overall body has balance
but yeh the short answer is the traps/shoulders arms is what people notice (but that is also the past of yoru body people see the most) you can tell if someones shoulders blow up cause it show in their width, adn arms everyone sees
no one really looks at your legs or back (except for how wide it is)