A few things that should be added to the Great Days article. (I'd add them myself, but it has been locked.)
So, as the title explains the post, I'll just start with the list.
1) The letters spelling out JOJO at the very start (The ones with all the protagonists inside) is a direct reference to the B cover of Chapter 321.
2) The word BREAKDOWN exploding and reforming is a reference to Joskue's anime theme, and the abilities of Killer Queen and either Crazy Diamond, or Bites the Dust's time loop.
3) Behind the first BREAKDOWN is an image of Killer Queen with mechanical arms, most likely referencing the technical aspect of bombs, or KQ's primary bomb, while the way it is posed is a reference to the pose it strikes in Chapter 326.
4) The afterimages left behind by the protagonists reference both their lasting influence on Morioh, and their many iteratio…