I didn't look at your portfolio (no offense). I did want to post for a few reasons
Hey! You got an audition to art school! That's great! That means you clearly are doing something right Treat it like a job interview
, not a visit with friends, no matter how casual they look or act. Trust me on that. Yes, the want people with talent, but they also want people who are willing to learn, who will work hard, who will reflect well on the school when they graduate off into whatever field they embark upon, etc.
I don't know how you dress, and art schools do tend toward more Bohemian or outlandish garb as the norm, but this isn't the best thing to wear on interview day. I wouldn't say suit & tie, but less is more in a situation when you are trying to make a good impression on others
Be yourself in the more-conservative-but-still-you version. I'd also say dress in layers- some places literally turn up the heat or try to freeze you out (puns intended) just to put pressure on the interviewees.
If you are bringing a physical portfolio (it may all be DVD's by now- I'm old) have someone who knows nothing about art flip through it. Anything that could slide, fall out, get wrinkled, etc. should happen then
, giving you time to clean up & secure it all before