Technically this shot has a lot going for it. Light, focus and exposure are great. However, I think the shot is lacking a clear center of interest or any dynamic composition to hold the viewer's eye for long. While you certainally met the challenge description and photographed bubbles, I just don't think this photograph grabbed the voter's attention very well.
Pleasing composition and definition of bubbles. Strong glare at lower left is a bit much - a little less of it could contribute more to the overall balance.