Flexing Upper Body to Appear Wider in Pictures
Your upper body can look vastly different in photos, depending on how you stand and how you flex your muscles. Your chest can look smaller in some pics and wider in others.
Here is a technique to make your upper body look as wide as possible...
Start by standing, spreading your legs to match the width of your shoulders.
Now concentrate on moving each shoulder out to the side as far as possible while keeping your shoulders parallel to your feet. Do not allow your shoulder to move forward or behind you. Move your left shoulder straight out to your left, as far left as possible.
Now do the same for your right shoulder.
When expanding your shoulders, do not allow your chest to move forward or backward. When you arch your back (push your shoulders forward), your chest appears smaller through the camera. When you push your shoulders backward, you flatten your pectorals.
You can test the parallel-ness of your shoulders by having a friend hold a broom, yardstick other straight rod lengthwise atop your shoulders lengthwise as you move them to the left and right.
Drawing by Bob Worthy
Isolate and Flex Your Lats
Now attempt to flex your lats (bring your lats out) without moving your chest or shoulders. Once again, do not allow your chest to flatten out and keep your shoulders from moving.
Flexing is challenging to learn, but will make your upper body appear larger in photos. Keep attempting this set of flexes until you have memorized them and can perform them with your eyes closed.