Here are links to pages on the official site which include pictures of the internal pages: Blue Lotus
, Broken Ear
and Black Island
According to their own forum, they have covered most of the Tintin books, from "America" to "Picaros", and should be releasing "Ottokar", "Shooting Star" and "Soviets" soon. I believe "Alph Art" will also be covered.
According to this summary of the series
, contributors include leading Tintinologist Philippe Goddin who, as head of the Herge Foundation, had access to the archives containing Herge's research and other material.
By the looks of it, I'd say that they are very similar to Farr's "Companion" or Peeters' "World of Hergé", but dealing with it on a book-to-book basis and thus containing even more details and more comparissons of Herge's source material and his illustrations: for instance, in "Black Island", they compare the scenes of Robert Donat handcuffed to Madeleine Carroll in Hitchcock's "Thirty-Nine Steps" to the Thompsons' situation in the book. (I'd always realised the pursuit-to-Scotland link to "39 Steps" but not that bit I admit.)
The books include articles detailing the development of main characters such as Haddock and Calculus but also supporting characters such as Muganga, the witch-doctor in "Congo" or Abdul, one of Muller's men in "Black Gold". They also dwell on the context of the times when the stories were published and Herge's research. There are examples of his sketches as he planned the stories and details about his other work, such as "Quick and Flupke" and "Jo et Zette".
This is interesting: leaf through the Broken Ear
pages and you'll find an illustration of Tintin in his armchair in his flat gasping as Ramon's dagger goes towards him. Never seen that one before. I assume it was from the original publication in the "Petit Vingtieme". The writers also note how from absolute darkness, Tintin, without leaving his armchair, somehow restores the light to see the dagger next to him - and no apparent sign of a lamp or anything.