Spheres are circles no matter what projection you use. Circles on horizontal surfaces (such as the top of the metal bit) should be ellipses half as tall as they are high (1:2 height:width), so yours is too squished. Similarly, you could depict the bottom of the bittle by having its round (=1:2 ellipse) base slightly visible through the front glass. Other than that, there's not much you can do with a spherical object that has an irregular surface.

Edit: I tried to illustrate what I mean about the 1:2 ellipses by editing the cap. Here's the result. I also tried adding in something like a shadow to show the bottom of the bottle but it didn't turn out well and I don't think realistically we'd be able to see anything resembling a circle with such an irregular surface.