Simple yet delicate, this piece is truly a pleasant to the eyes.
The color is cool and calm, but, at the same time, stores in it potential vigor. The golden spots are an excellent addition, bringing lively warmth to the artwork. The artist surely know how to play with colors.
The dimension is expressed very well with the decrease of opacity of the black lines. However, it would be better if the size of the 'farther' circle is reduced a little, maybe by about 10%, combined with a slight up right move.
In general, the use of blurred dots of light is brilliant, except for the shinier bunch right above the middle line, which is a little disconnected to the general flow of the picture. Rotation is what needed here.
After all, this is an amazing artwork, showing the energetic, mischievous yet elegant spirit of the young artist. His girl friend should be proud of this gift, for all the love and effort he put in it!