Wallace's words reveal his intent...
As the woman lies in front of Wallace, black drones hovering around her, he reveals his ambition to create a civilization that spans the stars:
"...Now let's have a look at you...we make angels in the service of civilization...yes there were bad angels once...now I make good angels. That is how I took us to nine new worlds. Nine. A child can count to nine on fingers. We should own the stars. Every leap of civilization was built off the back of a disposable workforce. We lost our stomach for slaves unless engineered. But I can only make so many. "
"That barren pasture, empty and salted...right here. The dead space between the stars."
This reveals that Wallace has been trying to create new models of replicants that can breed - but this woman replicant is another failed experiment. A tear falls from Luv's eyes suggesting that she knows or been witness multiple times before to the horror about to unfold.
"And this the seat we must change for heaven "
Wallace is quoting Lucifer in a line from Milton's Paradise Lost from when Lucifer was cast from heaven and into hell as a Fallen Arch-Angel.
"I cannot breed them. So help me. I have tried. We need more Replicants than can ever be assembled. Millions so we can be Trillions more. We could storm Eden and retake her. Tyrell's final trick: Procreation. Perfected then lost."
Wallace is implying he is in his own living hell in that he cannot replicate Tyrell's accomplishment of creating breeding replicants.
Wallace then imprints Luv with the work she has to do.
"But there is a child. Bring it to me."
As he leaves, he asserts the importance of of her replicant role as an "angel built to serve civilization."
"The best of angel of all. Aren't you, Luv?"