We pass each other in the corridor, I smile and attempt to catch your eye. I am saying that I acknowledge you, You are a human; I am saying "Hi!"
You ignore me. A faint flicker of your eyes shows that you saw me; but you focus steadfastly ahead. You've been working near me for 3 weeks now and I think that we should at least be able to say Hi.
You are an attractive woman who takes care of her appearance; maybe you have guys hitting on you? Maybe you are annoyed by the attention? But I am not hitting on you, I am just being a polite human being. I have little sexual or relationship interest in you. I do not want to bore you with tales of my work; I guess that you would not like Linux or IRC.
I am just saying hello.