I've got several cbz files. On those with single page images, everything appears as a single page in portrait mode. Pages of different sizes do display differently though. On some double-wide, I can pan around, or double-tap to get a single page.
I think the behavior depends on the format of the images in the cbz, in other words. Do you have any other formats you can compare?
Either I was holding it wrong or it was just not sensing the change in orientation. I checked again tonight and it works as I wanted (portrait for 1 page or landscape for 2).
Thanks for the reply.