We encourage entrants to include images, or graphic design, where appropriate, as they certainly add to a series bible.
Images included to do not count towards the page total but please ensure that the text of the bible is below 40p, and be judicious about including images - ultimately the quality of your story is key and no amount of great imagery can compensate for a poorly constructed narrative.
One note: do ensure that the PDF file isn't too enormous, it's advisable to use an online PDF resizer tool so that the upload doesn't fail.
Try and ensure your series bible is below 1mb in size.