Three live senses: (1) literal tiger pelt; (2) the spotted/striped pattern that resembles it —
虎皮蛋糕 'tiger-skin cake,'
虎皮青椒 'tiger-skin green peppers' (a Sichuan dish where peppers are pan-blistered to look striped); (3) the figurative 'borrowed prestige' from the chengyu
拉大旗作虎皮 ('hoist a big banner as tiger skin'), used by Lu Xun to mock people who use grand slogans as cover for petty motives.