Classic icons like, battery level display, settings, brightness, flash, or self-timer, just to name a few. The red border was created to keep that "red ring" theme throughout the deck. Red metallic ink can be found on the back design and faces of the cards.
The tuck was designed to mimic the aesthetics of a DSLR camera lens (a.k.a "Glass") while displaying information more related to playing cards. The red ring around the tuck mimics a professional line of lenses, known as Red Rings, which are classified as a higher grade of glass. This deck was created to spark the urge for shooters to get out and shoot.