It is not a manual or a treaty of symbolism, found in number on the shelves of bookstores. The authors are well known, say it themselves in the short introduction (10 pages) of the lexicon: "(...) offer a critical and distanced use of symbols in Freemasonry, more borrowing from the cultural history as an adventurous hermeneutics. " (Page 12).
In fact, they constantly refer to history to explain the appearance of the many symbols they have in their lexicon of "Bee" to "Travel." They do not engage in a detailed symbolic interpretation.
This small book provides a first interesting overview of Masonic symbols. It does not claim to be comprehensive (eg authors do not distinguish between the sword and the sword). The initiate will go for more information elsewhere. As for the profane, a bibliography, even briefly, would have been welcome in this QSJ, to me it seems.
I do not regret this purchase.