Yes, that's the schematic. To me the two look essentially identical save for topology and some imagined details.
I don't believe either of them are actually representative of a function warhead; see for instance https://images.app.goo.gl/aEBGKmAb8NsoAWe87, which suggests that in a real design the primary and secondary are inverted compared to the image shown in the blog post.
But I dug up the diagram you mentioned just because I was curious.
https://archive.org/details/introductory-nuclear-physics/pag...
Seems pretty different from the image in the linked post.