

There’s specific wave solder glue for smd components. Most likely all components were glued down. You can still see the off-white glue on the ICs in between the leads.
The parts that should not be soldered are usually masked off. Either with a mold or kapton tape/flexmask. Never Painters/scotch tape, since it will melt and/or burn.
It looks like a board where they indeed probably put the components on by machine, however without solder paste, since it was going through the wave solder anyway. But you would need to glue the components down then.
That’s why there is so much excessive solder. If it was printed with solder paste, it wouldn’t have this much solder.