you asked for an in depth comment on your shot for this challenge.
Very clever idea!!!
Your idea is an excellent one, just needs a little tweaking. The challenge description reads that it is for an appliance, granted you have the appliance in your shot, but without reading you title it would be hard to know that that was your main subject. This could have been avoided with a little more light on the subject. I know that you wanted the 'milk' to stand out, so some back lighting of the microwave would have worked here.
Your photo is also tilted, so combining that with the darkness almost makes it looks like it is floating. In post processing maybe playing with the exposure and a bit with the curves may have brought out a little more of the microwave. Your 'milk' is very sharp and the lines are crisp and clean
Nice clean microwave. I think for the challenge I would have liked the microwave to be your subject rather than the milk, as this is what I am drawn to.
poor execution of a cool sujet. either close up more or add light to the microwave to produce a framing.. or use a more exciting type of glas, maybe, 4