He later finds basically the same object with the caption "The multiple components of a nuclear weapon body are highlighted in this intentionally simplified mesh" from another publication of Sandia, making that theory kind of unlikely
[1] "The “obvious” answer, if my above assertions are true, is that it must not actually represent a thermonuclear secondary. [...] It could be some kind of pre-approved “unclassified shape” which is used for diagnostics and model verification, for example."
Oh i see what you mean. I took the theory to be that it is looking like a nuclear warhead but it doesn't have the right dimensions, or even the right arrangement of the components. Kind of like the difference between the real blueprints of a submarine (very much classified) or the drawing evoking the same feel but drawn by someone who has never seen the inside of a submarine nor does really know any details (not classified).
So a even a diagram that is abstracted and slightly fudged would be a huge departure from what the censors usually think is ok, which is weird!