It could possibly be assumed that a model’s runway make-up prep starts with some concealer or foundation—maybe a fluff of the powder brush. Not so: “Skin currently has to be flawless,” makeup artist Michaela Bosch proclaimed backstage at Christopher John Rogers’s vacation resort clearly show, where staggered swipes of assertion lipstick in very hot pink, deep aubergine, and a bright cerise punctuated exaggerated silhouettes. Bosch was busy supplying Nepalese model Varsha Thapa a facial massage with MAC’s Hyper True Serumizer, a new multitasking fluid that formally launches this thirty day period. When no one would confuse the behind-the-scenes chaos at Fashion Week for a spa, the comparison was there for…