This photo was taken in July 2016. Hayabusa of Tohoku Shinkansen bound for Shin-Hakodate Hokuto station in Hokkaido. The train was fully booked.
Actually all Hayabusa trains and Hayate trains on Tohoku shinkansen have only reserved seats. Therefore there is no chance to get on these trains at Tokyo station if you do not have the seat reservation. However, if you are taking these trains from Morioka station you can sit on the vacant seat even if it is located in the reserved car(of course you have to stand up and leave in case some one who has the seat reservation comes to your seat). Unfortunally there was no vacant seat until the terminal..... Which means I was standing more than 2 hours!
Not like trains in Europe, Japanese trains have three types of seat reservation:
1) All cars are reserved - Haysabusa, Hayate, Kagayaki(Hokuriku shinkansen), Narita Express and etc.
2) There are reserved and non-reserved cars - Hikari, Kodama(Tokaido and Sanyo shinkansen), Sakura(Sanyo and Kyushu shinkansen), Yamabiko(Tohoku shinkansen), Hakutaka, Asama (Hokuriku shinkansen), Toki(Joetsu shinkansen) and other non-shinkansen limited expresses.
3) There is no reserved car - local trains.
There are some people who thinks no need to make a reservation when taking shinkansen off peak, but due to Japan Rail Pass holders do not have to pay for the seat reservation, I strongly recommend to make the seat reservation if you have fixes schedule.
By the way, there are not so many baggage shown in the photo. A lot of Japanese are traveling without large baggage to their destinations, especially in case they are heading home and have a long journey. They send their large suitcases in advance by nationwide courier system. It is also convenient for foreign tourists too. You can send your large suitcase from your hotel to your next hotel. Just send your suitcase the night before check out and take a backpack with you.