So as we've all talked about, this issue is all about the so-called British Invasion, but more specifically Vertigo and that point where the odder DCU comics were shifted over to the imprint.
This starts with the cover, which is a pastiche of Dave McKean's style. As well as doing the covers for Sandman and many other Vertigo comics, McKean is a comic artist himself, most notably working on Arkham Asylum with Grant Morrison and Violent Cases with Neil Gaiman. He's also done a lot of album artwork, for artists including Front Line Assembly, Fear Factory, Alice Cooper and Tori Amos, and he's moved into directing with Mirrormask. It's worth noting his career to a degree as his style helped to define the era Ellis is exploring here.
Jack Carter is, of course John Constantine, and his funeral sees ersatz versions of the Metal Men, Animal Man, the Doom Patrol, Swamp Thing, The Spectre, The Demon, Brother Power The Geek, and someone who looks like Grant Morrison as The Author in Animal Man, amongst others. Dream and Death are seen on the way into the cemetary, and the superhero seen flying overhead and later in the issue is a reference to Marvelman. And of course, Alan Moore is officiating the funeral.
Drums' description of magic matches up with the cosmology of a lot of chaos magic and cybermagick practitioners. He sketches out the traditional pentacle shape while talking about it - and of course Grant Morrison and Alan Moore are occultists (and Neil Gaiman frequently uses modern occultists as reference points for his stories)
Carter's last line - Be seeing you - is a reference to The Prisoner.
Oh, and we've got a recurring motif at the start of the comic - Drums throws a bottle of WHAM cola at Jakita and she hucks it back at him, just like Snow did in issue 3.
OK, so my interpretation of this issue is a little different to what's been discussed so far. It's not presented chronologically, but Ellis is examining what he sees as three stages of British creators. The superhero, being Marvelman represents the earliest stages of the modern British comics scene - recontextualising older heroes and placing them in a morally complex and darker world - Moore would do the same with Captain Britain, and Alan Davis and Jamie Delano continued this after he left the book.
The second stage is the funeral. This is the point where DC started pulling British creators over to reinterpret their weirder titles, and the formation of Vertigo. Alan Moore is the core of this - hence he's officiating - and everyone at the grave is solely a DC character. Dream and Death being on the edge represents their one foot in the DCU, one foot out status.
The third stage is Jack's reappearance at the end of the book. This is Vertigo moving away from DCU and pseudo-DCU books into wholly original stuff. Apparently, Carter was originally meant to resemble Grant Morrison, but Cassaday changed it to Spider Jerusalem. This works to fit the metaphor as I see it, because Transmet started the year after Sandman finished.
So what does it all mean? Well it's Ellis commenting on his disdain towards work for hire, or working with corporate characters in general. Using John Constantine as the core character is particularly pointed as this issue was only a year or two after he quit Hellblazer over the school shooting issue DC refused to print. Personally I think it works, even if it's a bit soapboxy.
And as a result of all this, I really like the issue! There's a huge amount to unpack here, between the pitch-perfect Hellblazer pastiche scene in the middle, the cameos in the funeral scene, and Cassaday's art is increasingly confident. Now tonally it doesn't do great as a follow-up to issue 6 - I wonder if it was originally planned as part of Book 1, but Ellis decided to have a cliffhanger for the trade? there's more I want to say about this, but it's going to have to wait until the end of book 2.