Milk in the Dark

I scibbled some breakfast items a few weeks ago, and now I'm illustrating them in my spare time. I wanted this to look like someone is opening a door to a dark room. (All because I accidently turned the background purple, and I was like: "Oh well, might as well work with that.") It was a real challenge to figure out how the light would fall on the milk. I couldn't find any references, so I just dragged some anchor points back and forth until it looked kinda "realistic".