Why does she keep screaming over this?

She is nearly 5 months old as is infatuated with a empty pesi can she started playing with it after she grabbed it off my fiance when he finished drinking it. In the last 2 days it has to go everywhere she does, if I take it away she will start crying hysterically until I give it back. I tried showing her toys to play with but she only wants the Pepsi can, I washed it because she keeps licking it. When will she get bored of this can, and why is it so fascinating to her?? Thanks!!