I recently bought this comic album (which I didn't even know existed, even though I'd read much of his earlier work since it had been published in a Swedish magazine, which stopped around the time Streak of Chalk was published) and have read a few reviews of it on the net.
Reviews which mostly seem to miss the point.
Yes, the island and the people are possibly allegories and metaphors and symbols and is quite possibly analysable in that way. But for example there's also one comment that Raul can't tell dream and reality nor past and present apart which must have been written by someone who didn't read the comic carefully enough.
Agreed, it is weird in parts, for example if you're in a house on an island and someone says "there're no houses on the island" and "nobody lives on the island", do I think that's weird because I think in Swedish, read it in English and it's been translated from Spanish or possibly Galego and it's understood the meaning is no other houses? I don't know.
The album even has an instruction manual. It's that difficult to read, and apparently even harder if you're not used to reading comics.
First in it is the quote "You have seen and heard the same things as me, only we interpret the facts differently." (S.S. Van Dine, The Kidnap Murder Case)
In the afterword the author points out that "it's not excluded" that the reader after reading the last page will come to the same conclusion as Raul, the main character, and that it's also possible the reader may interpret what happened differently. He then goes on to mention that some readers may focus on details others find unimportant or suppose are due the the author's negligence or lack of rigor in telling the story -- and then discover a more complex, more disturbing and more surprising story. I did.
Here be spoilers.
This is comic album; you're supposed to look at the depictions, not just treat them as illustrations of what's being said.
Take a look at the last chapter. Raul returns to the island, he thinks, and two days after he left it. Note that in the second to last chapter Ana says that Raul has been gone for almost a week.
What do we see? Well, without looking for it I noticed two items: The trees weren't the same kind of trees and when Raul names two visitors on the island it's very clearly not the men he thinks they are. Then after the last page comes two naturalist illustrations, one of an oak species one of a seabird. And sure enough, when I go back through the last chapter we can see that the seabirds aren't the same species we've seen in the previous chapters.
The conclusion can only be that the woman he thinks pretends not to recognise him nor know who Ana is isn't the woman he thinks she is. I think I see differences between them too and the interior of the houses are probably subtly different.
The reader who notices this gets a completely different story than the reader who only notices Raul writes something in the last chapter which appears to have already been written in the first chapter.