One of the most remarkable comments in the linked tweet mentioned that an average book is big enough to hide a knife; but this is big enough to hide a small nuke (both literally and figuratively).

Also, being that its EU related, does that book represent every translation of the book, or is it just for a single language?
This has been asked in the tweet as well. But still, even if there are all (24?) main European languages included, each of them has an amount hard to grasp as a whole.
Another joke was: General content to the left; addendum after Wallonia to the right.

And another: The booklet design reminds of some "Holy Books" already out there...