A micro-aggression would be if you sit down for a performance review and somebody tells you that when you're sitting with clients you should smile a lot more. That's a micro-aggression because that comment would not apply to a male counterpart. “Smile more”, “be polite”, “be nicer”, those are micro-aggressions. They are subtle social cues. Usually, but not always, these cues are socialized through men and women to the women in the workforce to make them fit a certain part. They're not saying anything that's illegal; it's not overt harassment. I am not the best person to give you more examples right now.
On April 21st, 2015. See this statement in context.