Jeff Yang, writing for Quartz:
The bottom line is that in East Asia, the predilection toward using face-coverings to prevent exposure to bad air is something that predates the germ theory of disease, and extends into the very foundations of East Asian culture. In recent years, however, mask-wearing has become rooted in new and increasingly postmodern rationales.
Studies have found that among many young Japanese, masks have evolved into social firewalls; perfectly healthy teens now wear them, along with audio headsets, to signal a lack of desire to communicate with those around them. This is particularly true for young women seeking to avoid harassment on public transit, who also appreciate the relative anonymity the masks provide.
Masks are even becoming an element of East Asian style: In Japan, surgical masks bearing chic designs or the images of cute licensed characters can be purchased in every corner drugstore, while last month at China Fashion Week, designer Yin Peng unveiled a line of “smog couture” clothese paired with a variety of masks, from Vader-esque ventilators to whole-head riot-gear rebreathers.
This is so different in western where you only wear masks when you are actually sick to protect others. You will have different perceptions when seeing people wearing a mask on the street.