I have a lot of friends who see me as an unemotional robot. For example, a good friend from high school died in a motorcycle accident a few months ago. I was very calm showing very little worry or stress about it when I found out. My friends who were there were kind of shocked by how calm and worry free I was about it. To me, logically there was nothing I could do to bring him back so why worry about it? At the funeral there was some crying and mourning for him but that was it.
But even though I don't show a lot of emotions I do have a way to look into people's eyes as we have a conversation and I am able to meet them emotionally. I start to create rapport by talking at the level and speed as them. Make sure they feel listened when they talk by giving back feedback. It really works very nicely.
I'm a programmer with not much care to show emotions but meeting people emotionally is one of the most powerful things you can do in your social life.