I would say an introvert is more like "UM HELLO...PEOPLE" and the "EWW...PEOPLE" goes to Antisocial, because introverts can still talk albeit with limits.
Introvert: Social activity costs energy. It's fun, but they need to recharge.
It goes on a little more than that.
Extrovert: Being alone costs them energy.
Introvert: Being alone gives them energy.
So basically, we both get and spend our energy differently. However, introverts can learn to be extroverted, and extroverts can learn to be introverted, but it's like handedness, in that no matter how much one may practice, one hand will always be better or more gifted than the other.
Since I bury the needle on introversion, I can safely say that the above picture conflates the term introvert with antisocial. I, like many other introverts, do like interacting with people, but we usually require some "me" time every once in a while in order to recharge ourselves. For instance, the more people that are in the group I'm socializing with, the less likely I am to talk, and crowds can cause my energy to deplete even faster, so that after about an hour or two I start shying away from any social interaction and just want to go home by that point.