Transactions originate from the outside and feed in to the …

Transactions originate from the outside and feed in to the middle.

Blocks originate from the inside and feed out to the edges, being pruned and compacted as it spreads out, until all that's left is the headers for the very outer edges.

https://twetch.app/t/2f5f9daa1e1fbd77546c4777d8604bae0c48d72011cf18ed24819159bc333c6b