>How have you made the 70-200mm so small?

We were actually surprised as we started developing this particular product. The idea is that, with the introduction of the large diameter mount with the shorter back-focus distance, we were expecting it to be more suitable for designing wider-angle lenses, but it turned out to be very effective for designing this telephoto lens.
>but it turned out to be very effective for designing this telephoto lens.

In shot, you'll never see this size on tinny e-mount.