Dr. Cane, be careful, or you'll SCARE that CROW

I couldn't get pass the opening scene. Selina steals a brand new quart of milk and then after running away from the wallet she pinched, she's pouring milk for the cat in the alley. A) Why is the container of milk now almost empty when she begins to pour. B) If she is "cat" friendly she should know milk is not good for…