- Material handling - moving a part from A to B. Many of the parts looked too heavy for a human to lift. Some could probably be lifted by two humans working together, but that's a really bad use for humans and easy enough to automate.
- The presses and possibly some kind of moulding/pouring process, which obviously need to be done by a machine
- Spot (?) welding
- The coating/painting
So I'd turn the question around and say: It seems like they automated only a few key processes, and many of them because human labor isn't really an option. The presses replace many different production techniques, some of which could probably be done manually, so replacing those other techniques with "just put it in the press" is an advancement and it implies automation. The painting could be done by humans but the overall process would again be a lot more complicated. Automation for the welding is well established, and you want the consistency of robots.