Composition: Composition wise you have done very well. The cropping on all sides is nicely balanced and the photo has a pleasing aspect ratio. I like the way that the background fades darker as well. Locking the clips together shows the symmetry well.
Technical Quality: The focus and depth of field is very good. The shadows are well done (overhead lighting worked very well). The blown out highlights at the top edges are a shame, but also remind the viewer that the clips are glossy and reflective - overall they are probably better included than removed. The background is very well done.
Meeting the Challenge: You have met the symmetry challenge whilst still providing an interesting image. They have symmetry, without being "absolutely" symmetrical - which is nice.
Creativity: I like the difference in colour between the clips, despite their similarity. Locking them together was very good.
Border: The simple black border is nice. Simple is almost always nice when it comes to borders.
Overall: I like this photo - you've done well to make a basic object look appealing. I'm surprised this image didn't rate slightly higher actually. Well done.