It's amazing to watch moms teaching their pups. It can be quite scary at first when you don't quite understand it.
I have seen a pup misbehave and a mom hold their pup's muzzle shut to get it to stop nipping at her. If it persists and doesn't listen, they end up looking like they are swallowing their whole head.
They do not hurt them in the least but they do try to teach them manners and rightly so.
They are like sponges at this age and they soak up everything. It is up to their canine moms these last critical weeks to help them get a good start and then their humans in their forever homes continue it.
That is why you should never get a pup when they are 7 or 8 weeks old. The pups learn so much in those last 2 weeks that give them a good head start.
We got Shoshi from a breeder that sent her off way too early despite us saying no and it took her years to gain her balance. True she finally did but it took us, the pack and time to get that worked out.
So, learn from our mistakes even though those mistakes was imposed on us. I guess we could have said keep our $$ and not taken her too early but I suspect she would have been in someone else's home and perhaps not had the pack to learn from. I will never know.