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.

Nope, no Windows. Screens. The documentation talks to the fact the tube is made of steel, and I'm guessing it's not transparent aluminum.

"...made of steel..." "...it's not transparent aluminum..."

‽

http://phys.org/news167925273.html and http://en.wikipedia.org/wiki/List_of_Star_Trek_materials

Emphasis on displayed... It could be a screen.

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.

Hyperloop would be travelling as fast as a subsonic military jet and at treetop-skimming height, you would definitely get a migraine.

It could also just mean there will be picturesque scenery mounted on the interior.

(I'm not sure I'm joking)

The images would be pretty boring if the tubes weren't transparent.

I suppose they could cut holes in them in the image, but that's just like showing them as transparent.

It would be interesting if instead of windows, people wore (as an option) something like the ideal version of Oculus Rift, or some other form of VR/AR. Traveling 1Mm/h and it all feels like flying through the air in a comfy seat.