Personally, I think that white backgrounds are way overrated. I think each seller should use whatever background fits their shop aesthetic and presents their products in the best way.
That said, I have to agree that the photos that show some personality are the best ones. Stark white backgrounds are SO boring! I love the photos where you used the scale. If I were you, I would take that scale and use it in all my photos - not only is it a great way to display your particular product, but it would instantly add a sense of cohesiveness to your shop.
The only thing you need to do is figure out how to lighten up the photos - maybe start by using a lighter-colored background. I would also be sure to take the photos more close-up, it's difficult to see the product you're trying to sell when the photo was taken so far away. The scale is a great prop, but you need to make your product the star!