This is similar to the basic approach in Japan. On almost all long distance trains (both Shinkansen and otherwise), the seats are rotatable (or flippable). While they will normally be configured at the start of the journey as airline facing the direction of travel, passengers are free to change the direction themselves. So if you want a bay of 4 seats (or 6 where it is 3+2), passengers can simply switch one of the rows around.
People normally only do flip the seats around if they really want/need to face each other. Because one other happy result of the seat rotation system is that, in order for it to work, you need really generous pitch between the rows. So seats in airline configuration don't feel anything like as claustrophobic as compared to the UK. You also normally get a very generously sized seatback table. In contrast, if you do form a bay, you won't have a table at all. So there is nowhere to put your laptop / lunch / booze.
Normally the windows are alligned so that the centre of the window is in line with the rotational axis of the seats. So whichever way the seats face, you get the same view out of the window (which is often relatively small). If you have created a bay, then you'll get two windows for the bay (one connected with each row of seats).
The views from the windows are often quite restricted. But, there are a few important considerations:
- On the Shinkansen (with the smallest windows), there is often not much of a view out of the side in any case, because much of the track is in tunnel, and those parts that aren't often have high side barriers to reduce noise pollution. So you often can't see much at all.
- On slower trains, there if often an unobsured view out of the front of the train. So if the view is important to you, that's where you'll go.
- Even on trains with big windows, Japanese people will often shut the blinds on the windows to reduce sunlight coming in - for many people it is an automatic response to reduce the heat coming in, and to avoid getting a tan.
So unless you are on a train that is specifically marketted as a scenic train, or sat in one of the seats 'with a view' you may not get to see much in any case.