In short, it is the most handsome edition of Call of Cthulhu I've ever seen (in 30 years of collecting), in fact it's probably the best-looking RPG book I've ever seen.
To give you a sample of what it's like I'll post a few photographs here.
The endpapers and face page. The book comes with an internal bookmark.
Just a sample of the full-spread colour art featured throughout the book.
How to make a Mythos timeline look interesting.
Examples of how character professions are presented.
More full colour double-page spread artwork.
This edition of the Call of Cthulhu rule book is a true anniversary edition. Besides bringing back some of the wonderful art from the game over the past three decades, throughout the book there are entries discussing Call of Cthulhu supplements that have appeared during the game's history (Both French and English, from multiple publishers) .
(Click on the images to see larger versions.)