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The "large industrial base" is required primarily to highly enrich uranium (or plutonium).

A modern fusion bomb requires much less of that than the initial fission bombs.

So I don't know how much a state actor could infer from an image like that, if we assume it's a schematic of an actual bomb.

But it's just not true that someone in possession of detailed plans for how to construct a bomb isn't put into a much better position. They'll need a much smaller amount of fissionable material than they otherwise would with a cruder design.