Native mode means drawing from the Box without using an attachment such as a whip or tube.
This is the intended usage mode for which the Box was originally designed/optimized.
Anything that is provided as an attachment is due to user choice, not because it is necessary.
In fact, using the Box in its native mode has the specific advantages of 1) increased efficiency (since there is no condensation effect, there is no wasted/lost vapor), and 2) greater accuracy/sensitivity (since the temp/taste feedback is not muted by distance).
Magic-Flight strongly suggests that people at least try to use the Box native as this will provide a much more satisfying experience overall.
A minor design point with the Box is that it can be used in native mode while lying down flat on your back. The draw hole is positioned near the bottom edge of the Box allowing for one to hold the Box overhand (if you are right handed) and still be able to draw from the Box while keeping it level to the floor. Your lower lip would be on the bottom face of the Box and the upper lip is just above the draw hole. This makes using the Box accessible to people who are in a bed and cannot raise their head up.