I have studied your image and have the following to offer:
Composition/perspective - the subject to negative space ratio is really good here. Application of the rule of thirds is very well done. The relationship between the shadow and the subject is a very nice aspect - one does not overwhelm or take away from the other. The focus is crisp and both subject and shadow are well defined. Your camera angle to the subject is perfect - really makes your effect stand out.
Color - very rich color in this shot. Being on a white background really lets it stand out and gives it a lot of strength. The colors that are transferred to the shadow are just enough to give it its own character while not being to dark to fail. The subtle gradients in the subject are clear and displayed nicely (a tribute to the lighting).
Lighting - very interesting use of lighting in this image. It is just enough to make everything clear while not being too strong to cause flares/glares. The refracted light is a real nice touch and really helps make the shot. These are not overbearing either, so they don't appear as a distraction at all. Well done!
Challenge requirements - definitely meets the challenge requirements. While your subject is transparent, it is dark enough to give it depth and character. The shadow is clearly evident through the subject so transparency is obvious and the color in the shadow with the refracted light works well.
Overall/my opinion - technically this a very well done image. A strong subject with a unique effect are elements that should have helped this to stand out. Originality and a well executed creative concept are clearly evident. Very well done!
A neat abstract. Are people hammering you for it not being "transparent"? I'm being very lenient on this challenge so I'll assume that you can at least sorta see through that object (whatever it is). The technicals are well done. 7..rikki?
I like the shadow and the coloring on the foreground scissor(?) handle. The white backgroudn is a bit stark and takes away from the warmth of the object and shadow, but a nice change of pace from other entries. Shows creativity.