Quick descrip: link

Extroversion:

I am seen as “outgoing” or as a “people person.”
I feel comfortable in groups and like working in them.
I have a wide range of friends and know lots of people.
I sometimes jump too quickly into an activity and don’t allow enough time to think it over.
Before I start a project, I sometimes forget to stop and get clear on what I want to do and why.

Introversion:

I am seen as “reflective” or “reserved.”
I feel comfortable being alone and like things I can do on my own.
I prefer to know just a few people well.
I sometimes spend too much time reflecting and don’t move into action quickly enough.
I sometimes forget to check with the outside world to see if my ideas really fit the experience.

Definitely!

No question.

I don't believe she's AS introverted as people claim, since she only exiles herself into her room to protect others, feels miserable doing it, and would much rather be playing with her sister and subjects outside than spending time alone.

However? Yes. Even when she feels comfortable interacting with her sister and subjects, she seems to be by nature slightly more reserved, enjoy more mellow interactions, and needs to be by herself to mentally and emotionally recover from the effort of wearing "the queenly mask."

...we don't know. Elsa's personality is shaped by her powers, which makes me wish she never had them..sigh..

^Agree with you totally!

Her power controlled her, made her fear and shut herself. Yet in the end of the movie, when she finally can control it, she looks comfortable with lots of people. I believe that she's an extrovert. In fact, she actually hate to be alone, but she must do it.

^Sometimes even introverts can feel comfortable with people. Plus, I believe in the end she was comfortable with her power and not the people. But as dcairmont said "her personality is shaped by he powers".

The real extrovert is Anna.