Blake's Illuminated Books weren't created like most other books; they were created one plate at a time. Blake himself didn't always bind the plates in the same order and he sometimes added, or deleted plates from particular copies. It was poetry he was writing, and pictures he was engraving. Many plates can 'stand alone' as poetry or as pictures without the rest of the book.
This makes it possible, and perhaps beneficial to study Blake in increments. In a recent post I made, it was the picture that led me to study the context. In times past the words were available, but the pictures were usually inaccessible. The online resources have made possible viewing Blake's work as it was meant to be seen and read. With the plates we have the words and pictures together to complement one another. But don't expect the illumination to illustrate the text in the conventional way. His pictures may add to the text, may refer you to previous text, or lead to subsequent text, or may recall images on other plates and the context of the tale they tell.
Preludium to Book of Urizen
Here is a good example of a stand alone plate, a lovely image and a short poem to introduce the poem and the poet. But the words and visual images aren't meant to give us a static experience. Just as the woman and babe must stay in motion to remain suspended, we are meant to keep moving too. The air-borne babe takes us back to early plates in Songs of Innocence, and Songs of Experience; and will be seen again in plate 20 of The Book of Urizen. Another baby suspended in the air can be found in the Good and Evil Angels. The flames and the words, 'dark visions of torment', warn of what we can expect. We are left with questions, 'Who are the lady and babe?', 'Who are Urizen and the primeval Priest?' The answers will develop over time as Blake unfolds his complex myth of fall and return, disintegration and integration, death and rebirth. But first we can be satisfied with a graceful lady, her soaring child and the prospect of the 'swift winged words' to be dictated.
The irony of the of way Blake presented his material is that each individual piece was a 'minute particular,' complete in itself, but was essential to the organic body of the whole. How like each individual human being as a part of the Body of Christ.