That is an ugly sentence, and I hope the poetry of Felicia Hemans is better than the prose attributed to Stauffer.
I’d go with something like illuminating, projecting, breaking into fractions. “This really tells us something about how people were using Hemans and this book as a prism for viewing or projecting aspects of their own life”
“Lens” works too, but I like “prism” because it also includes the possibilities of de-focusing, or turning your grief into tiny points of light that illuminate everything else, or splitting your grief up into different colors of grief.
Or you could just say – every person reads a different book –