I feel like the most novel aspect of this image is an implication of the shape of the reflective casing at the far rear of the device--it seems to suggest a parabolic "shaped charge" sort of focusing element that likely helps to boost the neutron flux and initiate the "spark plug" from the rear at the same time as from the front.
Hmm. I've read every book on the subject and I have a feeling I've heard this arrangement already somewhere (shape of the mirrors used to direct the radiation pressure, not neutron flux).
