I'm not sure, but in section 4.1.2 of the PDF, it says:
Beautiful landscape will be displayed in the cabin
I took this to mean that there would be windows.
I agree about not wanting to look outside, though. I've travelled on the shinkansen in Japan (which go ~ 1/3 of the speed that the hyperloop is planned at) and it was really hard to look out of the windows for any length of time.
It all depends what there is to look at. If you are traveling through the forest area, among the trees, the scenery would fly past in a blurred picture if you look out your window. However, if you are traveling over a vast land with Mt.Fuji in the distance, that would be something to look at.
I traveled in the ICE in Germany, also about similar speeds at the shinkansen, and some of the views are breath taking, and some views gave me a migraine.
I agree about not wanting to look outside, though. I've travelled on the shinkansen in Japan (which go ~ 1/3 of the speed that the hyperloop is planned at) and it was really hard to look out of the windows for any length of time.