"In this situation, the child needs to feel cared for, even though their parent isn't supplying them with that, and so they repress the negative aspects of the "object," the mother, so they can hold onto the positive ones. In the child's mind, the idea of the mother is being preserved and destroyed at the same time."

Repress -- inhibit the expression or development of something.

I'm thinking the child develops conflicting feelings about the mom and in order to survive, it has to split the positive from the negative which then damages the development of object constancy.

Lol I don't quite get it, either. I'll need to look ìnto it again.