Ahhh. The LOC lessons. The examples you show are embedded. They just follow print.
In guidelines for attributions and source citations, the placement is for material that appears around the material (in the margin, bottom of page, on the line after the text, etc.).
If your 3rd scenario was:
“It was from the crashing of waves on the shoreline, the spray of water
forming dots on the sand spelling out ‘you crazy’, that I knew it was time
for a break.”
—Confusionville, 24
Then it would be blocked in the fifth cell. It is not part of the quote, story, etc. It is separate.