The first time I looked at this, I thought that It was a piece of highly sophisticated 3D Modeling and rendering and when reading your description that you had only used light painting and slight colour modifications, I was blown away.

As ~Wenxie said, the contents of the cup seems to resemble that of a starscape, perhaps a nebula. An explosion of light sitting in a small glass of liquid, It's colours are amazing, In addition, where you finish out the image by using a well contrasting colour, blue (exemplifying the binary of hot and cold), you create a very strong image that will catch the eye of anyone who passes by.