This is a weird one, and is either a bug in the Magazines app or some hidden option that got changed I can't discover how to change back.
The sample Popular Science that came with the device at one time looked pretty much like all the other sample magazines, but somehow, somewhere, it got into this weird state in which the screen seems to be showing only 1/4 of the page, and only the top half of the page is accessible at all, you can't shove the page image up to see the bottom half. Here is a sample (click on the thumbnails to see the full sized screen shots):
In contrast, the Esquire magazine is still showing me full page images:
So, bug?, or impossible to find setting?
I'm also not the only one to see this. This android forums thread shows others have seen the same thing.
Update:
After sitting overnight charging (no changes made by me), I looked at Popular Science again this morning, and now the pages are back to normal (picture taken with phone as I'm not near my system with the SDK installed right now):
It is almost like it works fine in the morning, and goes funny in the head in the afternoon :-).
Except now it is evening, and it is still working fine, so it isn't time of day either. I guess it is just a mystery never to be solved. I got some mail from google suggesting that I goto Menu > Settings > Applications > All > Google Play Magazines and choose Clear data to flush the cache so I can re download the magazine and see if it works better. I guess I'll try that if it happens again.