I dreamed a decapitated head

yesterday, i dreamed about me and a girl(this girl looked exactly like Lee Ji Eun, korean singer) went to mcdonald to buy foods. After we bought the food, the moment when we step out from the restaurant, i saw a black plastic bag fall from above out of nowhere so i just ignored it. Then the girl saw a human head in the black plastic bag.

When i looked at that head i was shocked(i can still feel that shocked after woke up)and i dont know who is that head. . . . long hair with big eye looking at us(i can still remember that face). . . . . i cant remember most of the part and sorry for my bad english. . . . can anybody tell me what this means? ? ? this is the first time i dreamed a decapitated human head