What does the phrase "book that, like its subject, is haunted by her absent presence" here?

I think there is additional context missing, but here are my thoughts based on only the available paragraph.

"...I mourn her and wish she were still with us for many reasons, not least to see the publication of a book [This Orient Isle - Elizabethan England and the Islamic World] that, like its subject, is haunted by her absent presence."

I assume that this passage is written by the author of the book This Orient Isle - Elizabethan England and the Islamic World, maybe in a dedication or foreword. Based on the piece that says "that, like its subject is haunted by her absent presence" and the previous reference to her intelligence, I presume that Lisa had interest in or studied the subject matter of the book. The sentence implies that her influence on the book and the subject matter were great enough that her absence impacts both negatively.

I looked up the title on Google Books and it appears it was published a year after her passing. I think the author was trying to write a poetic and beautiful tribute for their lost friend.