Guys who pass or are passed by women they would like to smile should: smile in a friendly way. That is all.
Exactly. And vica-versa and every which way.
I don't want to speak for WAB, but I suspect he would be just as pleased (if not more so) if the women he referenced simply smiled pleasantly at him, maybe included a cheerful "good morning" rather than telling him what to do or feel (however pleasantly or with good intentions they may have done it)
No, not really. Being "told" to smile was taken by me, on every occasion, as a recognition of myself as a person with the right to be happy and express joy. Hello and Good Morning are generic and we say these things to complete strangers without any real feeling: it's out of sheer habit. I can't recall a total stranger ever telling me to smile, however. These were co-workers, friends, acquaintances.
I would object to the word "told" as if it were a real demand, as it's actually not. It's a suggestion. I would also say that I do not think for a second that it's a good way to greet a complete stranger! Someone telling a random passerby to smile is a little fishy - though it hardly constitutes sexual harassment (see below before getting upset).
NOW: if any woman (or man) is being literally "told" to smile, and if such a demand is given in the tone of a threat, then yes, this would constitute harassment!
I've never heard of a man telling a woman that if she didn't smile she would be harmed, assaulted, or raped, at least not outside of cases of actual offenders before or during the commission of their crime. Sure there are many assholes out there, but let's not pretend this is normal behavior for men, because it isn't.
I daresay there are a few men hereabouts who have walked on eggshells through threads like these, or simply avoided them, due to the risk of being branded a misogynist, a whiny manbaby (or some such), or having one's thoughts completely misrepresented, or just misunderstood, for the simple fact that there is so much emotion involved, and emotion is often stronger than reason.
This is a discussion board, and it's presumed that threads are initiated with the idea of the topic being discussed, which entails a variety of views being brought to the table. Naturally, we should condemn racist or misogynistic views, when that's what they are, but not all posters maligned as racists and/or misogynists deserve those labels, and not all off-the-beaten-track posts come from a dark, secret place.
I personally don't tell or ask people to smile, unless they are close friends or family; and I would never say anything to a random stranger beyond the generic hello or hi - and only as a response, when they do it first.