HUD Config
This part of the HUD shows an abbreviated version of your ship's current loadout. In the top half, your current weapons are displayed. Weapons whose group is currently active are surrounded by a bright teal border.
The bottom half of this display shows the contents of your cargo hold (as icons). To see more details about your cargo loadout, you can open the Cargo window in your PDA, which is by default bound to the 'j' key.