They drive every reader's interpretation of the text.
Millions of investigators (and members) look at these illustrations. Far more people see these illustrations than ever read the Introduction, let alone the text itself.
Illustrations surely attract interest in the book, which is great, but we have to realize that first impressions are lasting impressions.
The current set of illustrations tell readers the Book of Mormon took place in a jungle with Mayan ruins. But when they read the text, it says nothing of the sort. No jungles. No massive stone pyramids. No Mayan culture.
The result: disappointment and confusion at best, disbelief at worst.
As I suggest in the post, it would be very beneficial to re-think the illustrations and focus on what we do know about Book of Mormon geography; i.e., that Lehi left Jerusalem, that he traveled to the Arabian peninsula, and that the Hill Cumorah is in New York.
Suitable artwork already exists; indeed, it has been used in the official versions in the past, as I show in the post. It's an easy change that will make a big difference in how people receive and understand the text.