ON a blazingly hot sunny day in Los Angeles, eight people are inside One Take Studios on a desolate street, prepping for a photo shoot. In a brightly lighted room, hair stylist, Sienree Du (Ri to her friends) tries to build a fake mohawk out of a model's long, brown waist-length mane. The petite stylist joked with her muse, ''Your agent didn't tell you I was going to shave your hair?'' Ms. Du is a stylist at the Angus Mitchell Salon in Beverly Hills. Today is her day off, but instead of spending prime sunny hours at the beach, she is working on a shoot for the online magazine, Vamp'd, so that she can build her portfolio, or ''book.'' [ABSTRACT FROM AUTHOR]