First of all you need to be a 501st member with the Stormtrooper costume.
Then looking at the photos, you need to include pictures from the front, side and back with your arms in the down position as if standing to attention so that your arms do not cover most of your body so that the costume details can easily be seen.
Also to be shown in photos are the blaster details, helmet close ups showing colour of lens and mic tips and we need to see a helmet off shot.