They are very small, approximately 18 x 25 cm. Inside is basically a scan of the original book. Sometimes two facing pages of the original are reproduced on two facing pages of the Errata edition. Other times four sets of facing pages from the original (for eight total pages) are reproduced on two pages of the Errata edition. So the original is very reduced, but you get an idea of the setup of the original book. Where the original contained text, that text is reproduced at the end of the book. There is also some additional text giving information about the photographer
I'm not an expert on printing quality, but it seems fine, bearing in mind the reduced format.
In my opinion, it's a nice idea, and a good way to get the sense of what the original book was like. But I found it too small for my tastes. I found it not a good way to read the original book. It's more of a record of the original book. And to be fair, I think that was the idea of the project. He wasn't trying to republish the book in a new edition, but more to record what the book was originally. It's kind of a meta-book.
-Laura