This is a client's actual before/after comparison photo. They sent me this photo from their website, that they actually were using. The bottom is ours from a shoot we did together.
You can see, in the client's photo, that the crop is very tight, which means it actually cuts off the edges of the products. If you wanted to extend the image for an ad, you couldn't because the jars are cut off. Also, it was taken at close range with a cell phone camera. I can see this because of the distortion of the shape of the jars.
The top photo was lit from the front, which is bad for glass products because it shows the reflections of whatever is in front of the product. Proper lighting for reflective items is from the side and back, which also adds to showing the shape of the item. In the top photo, the jars look flat, whereas in the bottom photo, they look round, and you can see the angle of the top of the jar, thanks to the reflections.
PS - the top photo was such low resolution, that I had to make the other photo so small to match... so when it gets expanded in the full page layout on here, they are both blurry.
What do you see?