Empaths often mirror other people and reflect it back to the person. I think this is meant as a deeper spiritual growth thing but more often then not, most don't see it. We usually don't see it until after the fact either because the energy is to strong. Everyone is like a natural satalite walking around with energy. Some receive others energy really strong, some project energy really strong, and other receive and the project the same energy. Sometimes it's the surface emotions, but alot of times, it's the things that are deeper, the things that the other person tries to hide that we pick up on and then give it back. For me, alot of it if proximity, the closer they are the more I channel their energy and the more I project it. They could seem normal but holding alot of anger, and then when I get around them, I feel that anger and next thing you know I am angry at the world. When I walk away and refocus my attention on something, I'm like, "where did that come from?". The way they feel is the way we express it and it usually so extreme they get scared and walk away. Eventually they will see the lesson within even if they don't actually see what had happened or fully connect the dots. For example, your friend was cheated on and they want revenge on their bf. So this anger builds and builds. Your hanging out with them and you start feeling this anger build inside of you. They are thinking " I really hate him! I really want to hurt " hurt him the way he hurt me!" and you start yelling " he needs to have his intentions ripped out and feed to a school of sharks! Then your friend looks at you like you have completely lost your mind, makes an excuse to leave. She goes home, listens to some sappy loves songs, crying her eyes out over a bowl of chocolate ice cream and the grieves. She starts to feel better and moves on.
Alot of this if, I think, because when we "recieive" the energy, we take some much of it into ourselves and then when we project it back, they often see the extremeness of it and it changes their thought pattern of the situation. They don't often connect the dots of what is happening, but they do see the extremeness of your behavior of the situation that more often then not, it shifts their perception of their situation.
It may not happen everytime. If it does, you may want to try a stronger shield so you aren't recieiving to much energy. The shield will also help control the amount of energy you are projecting. If you are getting alot of negative responses from people, it may be time to do an aura cleanse.