This is something I've been curious about and am interested to hear if this is something women consciously do.

I've noticed in many scenarios, at the grocery store, walking down the street, etc. that, pretty frequently I'll make inadvertent eye contact with a woman who is / was smiling about something (maybe she just looked at a photo, thinking about a joke, is happy about something etc) and will upon meeting eyes with me (again I'm not trying to stare her down, this is just a momentary thing) her smile just instantly disappears and she goes either dead eyed blank face looking straight ahead, or sometimes even full RBF mode.

Just today, I was in line at a grocery store and a woman was on her way to one of the cashiers, and I was going to actually apologize because I thought I had cut her by accident, while she was smiling and looking at the cashier, she caught me looking at her and just did that whole 😃..😑 transition.

Feels bad man.

This shit makes me feel sub-human and I'm guessing many men have experienced this before. It's another one of those small daggers that says to men "You aren't worth acknowledging, much less being pleasant to.

So, what is the mental calculus that is going into this phenomenon?

Reference here:

https://youtu.be/Prz7que9MT4?t=106

EDIT: Final thoughts, after reading most of these responses, I totally get the primary reason the women that consciously do this, do so. I would too in that position. Still, I would ask women to consider that this is one small part of men's cold existence that takes a toll over time. It's one subtle, but constant reminder that you are seen as not worthy of kindness, but of suspicion. I honestly believe, regardless of the reason of the cause, this kind of shit adds up and takes a toll on young men's mental health. I can understand it as I'm older, but I wonder how young men internalize phenomena like this.