Symbolism, Imagery, Allegory
There's Always Room for Cello
Mia loves the cello. She loves playing the cello more than she loves her family, her friends, or her boyfriend. To her, the cello is "almost human" (1.32), and if she plays it right, "it would tell you its secrets" (1.32). She repeats this sentiment later, saying that "there is something so human and expressive about it" (4.49).
Mia's reverence for the cello shows us how important music is in her life. It isn't a visit from her best friend, her boyfriend, or her grandparents that causes her to regain consciousness. It's cello music, the soundtrack of her life.
There are positives and negatives to this. On the positive side, this is Mia's passion, and the cello represents for Mia life lived to its fullest and on her own terms. On the negative side, there's a sense that the cello is more "human" to Mia than the actual humans in her life, Adam kind of excepted; it's like Mia doesn't process the fact that others care about her, because she's so wrapped up in herself. Maybe coming of age for Mia will be learning to integrate both aspects of her life.