The Grimoire of Armadel is mostly pictures. Its bulk is a series of sigils, each attached to a spirit or angel and a short statement of what knowledge that figure can impart, with only brief accompanying instruction. What it offers is not command over spirits for worldly ends but access to specific pieces of understanding: the fall of the angels, the nature of the elements, the hidden sciences, matters that are theological and speculative rather than practical.
That places it at the contemplative end of the Solomonic material, closer in spirit to the Sworn Book than to the pact grimoires, and it is why the text is often described as devotional. The sigils are meant to be looked at and used as the focus of the working, which makes the book unusually dependent on the accuracy of its images: a grimoire of conjurations survives a bad copyist, a grimoire of sigils does not.
It reached English readers through a translation by Samuel Liddell MacGregor Mathers from a French manuscript, made in the late nineteenth century and not published until long afterwards. Mathers is the translator here and not the author, a distinction that gets lost when the book is described as a Golden Dawn text.