Glad you kept background well blurred and I like the branches redirecting my eye back to the bubble(subject) Lighting and reflections on bubble work very well. Its hard to get a bubble to keep a viewers attention but with the reflections and small buds on branches it does accomplish this reasonably well Good job!!
Nice use of DOF here. And an imaginative place to put a bubble...! To be honest, the first thing I thought when I saw this was; How did you manage to prevent your reflection appearing in the bubble? :-)