Enjoying this “original” piece as it deserves requires
clicking on it to enlarge it.
This is a funny little scene of the Hitchhiking Ghosts meeting their concept-art counterparts, hence the title; there is no explanation given, though time travel is probably involved. At any rate, it is a fun occasion to compare the originals with the current models. The strip is mostly based on a specific Marc Davis concept-art for the trio:
The whole strip is something like "Brides of the Mansion", and contains similar mythology gags. The Casper-like Ezra of the first concept arts is deemed ridiculous by most fans of the "skeleton" Ezra, hence Ezra's snarky comment to his concept-art equivalent. Similarly, an unwelcome change in recent design was the loss of Phineas's coat, which most fans think was a bad idea (hence Phineas asking his old counterpart for a spare one).
It can also be noted that Gus is the only one of the ghosts not to talk in this piece… A nod to "Prisoner's Escape", I wonder ? Perhaps it all comes from the fact that Gus doesn't have a mouth at all in the original Marc Davis concept-art.
Well, at any rate, an interesting nod to the characters' origin, with good art as always and some nice mythology gags.