blua:

“People order each other to smile because they feel uncomfortable around people who are not smiling, especially when those people are women (or are read as such). Women are expected to be nice and sweet, to make other people feel comfortable. A woman who says ‘hey, I think there’s a problem here’ is being ‘negative.’ A woman who doesn’t smile while she’s being harassed is ‘humourless.’ A woman who prefers to stay focused on tasks is a ‘cold bitch.’ Significant gendering is involved here; women have an obligation to look and act a certain way and when they don’t, they need to be hassled until they do.”

— S. E. Smith, Smile! (Your Face Is Making People Unhappy)