I'm not a twenty or even thirty or forty but fifty something barista, shop owner and roaster but I wouldn't be caught dead wearing a bow-tie! I do of course get your point. And compromise from my long ago totally long hair rebellion followed by years of Corporate American and short hair respectablilty and now wear my hair short yet long, kept short front top and above the ears yet long and getting longer in the back, sides above the ears yet over the collar in the back. And got a coffee bean pierced earring for Christmas. No tats yet, but some coffee ink likely in the future. But will be in a reserved way.
In Europe, where baristas are generally more respected as professionals in a legitimate career path, the baristas I've seen present themselves very differently. Many are middle aged men, and often they are wearing very dapper get up, some even bow ties. So, ask yourself honestly who gets more credibility from the general population right off the bat...the frumpy 20 something with facial piercings and purple hair, or the handsome middle aged guy in the bow tie.