It's about understanding your own tastes and goals better.
Identify and elaborate on what you like about X artist's style, artworks.
Ask yourself what sort of art you want to do, and what appeals to you.
A question I like is "hypothetically, if I were forced to make an unified artbook on a theme, what would the artbook be like?"
This leads on to further questions: what am I interested and committed in drawing extensively, what is the mood or feel of the overall artbook, what effect would I like my art to have on the reader as a whole, etc.