I don't know about the bubbles, but I do like the composition of this image. The glass and straw seem alone in the image, but then you see the head in the shadow. Nice.
Oh no..... My mother always yelled at me when I blew bubbles in my milk/chocolate milk, 'cause it would get so messy. Better hurry before your mother gets there!
I think that how you used what looks like chocolate milk, instead of white, was probably a good idea. The picture might have had too much white otherwise. The shadow of the face blowing bubbles brings the concept together, without obstructing the image with an actual face. I think more bubbles would be nicer, though. Chocolate milk has a lot of bubble-potential. 8.