"Lalala ~ One big pineapple sell for Two cents, four big sack five and Half Mao, Xian Ming engage in autocracy everyday(I think this one means to monopolize), Lin Yu Ren sets a basket, half a catty two hundred fifty... I just translate it literally, but really? Selling pineapple?
林御 and 人设 are 2 separate terms. 林御 is a name while 人设 means "character" as in from "out of character". Probably the song was mocking the person for being two-faced.