Thanks for the sample!
Yes, now that I look at it I see what you mean. I note a few things:
- The images used in normal ePub mode are selected illustrations from the magazine, rendered at lower resolution.
- The "full page" images contain the same illustrations but usually at much higher resolution.
So all things being equal, you should see more detail in the "full page" versions.
I opened this file in iBooks on my iPad and got the normal ePub version and I was able to zoom all of the illustrations. However, the ePub illustrations have such limited detail that zooming was kind of pointless.
If you view the normal ePub version in any other reader, image zoomability will depend entirely on the features of that reader. As Jellby said, any reader app based on ADE will not support image zooming. Your EVO's reader app presumably also does not support image zoom.
Regarding the ReplicaMap version, this seems to be a special feature specific to the Nook. It's not in the ePub spec, and iBooks does nothing with it. I suspect that the Nook is just opening the images with the image browser rather than the ePub viewer. This would explain the zoomability.
Anyway, the practical upshot of this is that zooming images in normal ePubs is apparently not supported on the Nook. If you want to zoom your own books on Nook, you're going to have to create full-page static layout images and hack ReplicaMap. Simply embedding images in ePub probably won't work.