Ok going back to the beginning of the video, I agree with whomever said that it did not seem that architecturally, and based on the video that showed the window, that it could be her room that he zooms in on. To me it seems like there is another window or door or mirror or something on the far wall of said room, which would not mesh with the location of the window in the other video.
Now addressing the pocket, I have put many paperback books in my pocket, in fact almost everyday I have one there. Never have the bent in that way, they always conform to my leg. And the only way it could remotely, imo, look like a phone would be if the phone was flipped open, or a really small version of the '80s cell phones, you know those big things with the mouth piece that kind of protruded from the phone. Maybe it is an extra camcorder battery.
And I have yet to listen to the audio, can't really hear anything in the video though.
Edit: just listened to the clips, maybe order of the beast or reese's piece