This photo was made with one release of the shutter. I am actually shocked that the sides and top of the glass in the rear are not refracted by the large glass in front of it. I think the stem and base of the rear glass are made to appear smaller due to refraction but I'm not positive. I can't explain any of it (because I'm not a physicist) but I'll take all of it.
Please click the photo to appreciate the mid tones in the larger size.