...Sable snorts.
"I assume you have to say that for some sort of testing protocol reason," she says, "because really."
Which means there is a way through the puzzle without just killing the Emancipator and sauntering on through. Perhaps that big square hole in the wall above the Emancipator is relevant. Yeah - blue portal behind the cube, take cube through onto orange-portal platform, thank you telekinetic portal widget, put down cube, send blue portal through convenient wall hole, pick up cube, put cube through portal, follow cube through portal, put cube on button, walk out door. She didn't even have to put down her radios.