Three of the panels show this yellow card in a mirror held along some line (upright, flat or slanting). Which panel is NOT a mirror image of it?

Every mirror image flips the card over, which reverses the turning sense of the dot, the L and the orange flag. (d), (a) and (b) are such flips (upright, flat and slanting mirrors). (c) is just the card turned through three quarters of a turn, so no mirror can produce it.