Highly polished beveled edges reflect light in two directions for better legibility and emphasize needle-sharp tips, lending an air of Germanic precision.
While Apple and Palm talk up the legibility of screens on their diminutive devices, the nano and z22 have relatively low resolution when compared with more expensive models.
It also particularly creates a natural white color which reduces eye fatigue and greatly improves outdoor legibility by eliminating the difficulties of viewing the screen clearly under outdoor or bright light.