A nonstandard die, or an artistic error?


While exploring the details of Bosch's The Garden of Earthly Delights, I noticed in the screencap above that the die on the woman's head has the "2" pip and the "5" pip on adjacent sides of the cube. I wonder if the positioning of the pips was not standardized in the 16th century, or whether Bosch was unfamiliar with dice and made a simple error. Anyone know?