In many cases in order to form an image in a viewer more than one image is requested and tiled together.
How does tiling work with IIIF?
Visit the tile exploder.
Here's the information for the default image used in the demo: https://dlcs.io/iiif-img/2/1/e75d37c5-40a1-48a4-b61b-52ac7aa26849/info.json
Try entering this image to see how it is tiled: https://iiif.lib.ncsu.edu/iiif/segPap_022/info.json
How does the tiling differ between these two images? Any ideas why?