I did this last night, and my critical eye was in high gear (do eyes have gears?) and I saw all kind of problems. This morning I was fresher. It looks better. Glass is deucedly difficult--and a lot of fun--to paint. It has reflections and transparencies that require you to really look at the shapes and colors. The cool part is that, since you know it's difficult and kind of abstract, that almost makes it easier: you turn off your literal brain. By contrast, the apple should have been easy, but I kept seeing reflections in it that shouldn't have been there, but were.
UPDATE: I darkened the background. The composition needed the kick.