Why Such a Low Stance?

One of my friends was looking at some of Shifu's videoclips and asked me "why such a low stance?" Frankly, for this particular movement shown above I am not sure, but in other sessions of classes, Shifu has gone very low in other movements and explained and DEMONSTRATED to us the effectiveness of going into such a low and deep stance on an opponent. At times, the lowered position seems to apply greater pressure onto a limb such as the opponent's leg or arm, or neck... at other times, the lower stance was to neutralize a given attack by an opponent. The bottom line though, is that there IS a functional reason for being able to achieve those lower positions. It may be unnecessary for most people but for the serious Chen student who is learning application and true understanding of his form, then it should be something that is striven for. By the way, that movement is from one of the Chen forms I will be learning much later.
J