|This is actually quite scary!!
I think the problem here is mostly the lighting. It is very flat, so shows no depth to the pickle. With lighting more to one side it would create a highlight on one side and a shadow to the other, making the object look more 3D. This would create a shadow on the paper, but with a defused filler light, it would soften the shadow whilst still keeping the depth that the side light creates. I also think the shot is somewhat underexposed, hence the dull grey colours of the background, rather than a nice bright white, which I think is what you were going for? Kind of like a product shot? That requires you to overexpose a little, which shouldnt be a problem since the object is quite dark. Do you have a desk lamp? I find them very useful as you can position the directional light just how you want. Printing paper over the flash of your camera can work well as a diffused fill light.
I would definately recommend getting a desk lamp/reading lamp. They can be picked up fairly cheaply from stationary shops and pretty much anywhere :)
Post processing can also help A LOT! In this shot, I would have first of all adjusted the levels to get the background whiter, and make the pickle "pop" more. I would then probably have increased saturation to give some boost to the rather dull colour caused by the flat lighting. A quick unsharp mask (at about 130% / 0.3 / 0) to the pickle would help bring out some of the detail too. Here is a quick 2 minute job I tried on your shot. //www.dpchallenge.com/image.php?IMAGE_ID=270752
Don't forget, it's an advanced editing challenge, so you can make selections. I selected the background with a feathered selection and adjusted the levels till it was white. I then inverted the selection, and adjusted the levels on the pickle, creating more contrast in the darker areas and boosting the colour significantly. I then applied USM. I think you'll agree that although it's not perfect it does improve the shot significantly.
The other thing I think is wrong with the photo is the composition. It is extremely centered, which doesnt create any interest. Along with the dull grey background and the flat lighting on the pickle (which in itself isnt the most attractive thing!), the end result is a photo which is really not very appealing to look at.
I hope this helps :)