Although she has been shown to very emotional and quite expressive from season 1, Tina was always content being in the sidelines. I know she is acting out now but she only expressed wanting more attention a few times (Props, Diva, Frenemies) and it took her three years to stand up for herself (Props). Tina appears to have always had expressed the feelings that are nearer to the surface (Dream On) and kept deeper feelings to herself until she couldn't take it anymore (Props). She even went as far as to fake a stutter to stay distant to others, and she doesn't really care about how she is perceived by anyone in school besides the glee club. It seems as if Tina wants more attention from the glee club, because they are her friends, but she doesn't have a need to be popular in school. Also, she seems to only share her true feelings with the people closest to her (The Power of Madonna, Dream On, Diva), and seems to stick to her close friends, valuing deeper friendships rather than many friendships (Artie, Mike, Blaine) and appears to be more comfortable expressing her deeper feelings when she feels that no one, or not many people, is listening to her (Diva is a good example of this).

She used to be introvert, but now she's extrovert in a very irritating level!!!

Introvert Seasons 1, 2, half of season 3.
Extrovert Seasons 3+

yeah she has grown up and i like it!