NEW YORK — The Mondi Group celebrated its new image with a cocktail party and informal show last week. Although the company revamped all six of its lines for fall-winter, only four were presented. Chris, geared to the hip customer, provided fun, with supershort black and white optical print suits and cute pastel jumpers. Portara, the young working woman’s line, showed chiffon dresses that can be worn for both day and evening. The Elementi collection puts new life into knitwear with simple maroon dresses paired with textured sweaters. And classic Mondi fans can sign on with shaped military jackets and pants, complete with officer stripes.