Rick attaches a biosensor onto Rachael's cheek and shines a sharp pinpoint of light into her eye. He explains that the test will measure her responses to a variety of questions. And time is a factor.
Rachael guesses, correctly, that her verbal responses count for nothing and nada. It'll be the way her body responds that truly counts.
Rick asks her a series of questions dealing with various social situations—most involve, in some manner, a dead animal. (Check out our "Symbols, Imagery, Allegory" sections for Voigt-Kampff and Animals for more on why this is important.)
Rick proclaims her an android, but Eldon assures him she is 100%, genuine human being. Her empathic handicap is the result of growing up on the spaceship Salander 3 and learning about Earth through library tapes.
Rachael and Eldon both suggest the possibility that Rick could retire a person with this faulty test.
Realizing he was set up for failure, Rick packs up to leave, but the Rosens aren't done yet.
They offer him a deal: They'll give him the owl, one Scrappy by name, if he keeps quiet about the Voigt-Kampff's failure and carry on with his work.
But the way Rachael refers to the owl as "it" gives Rick an idea.
He tells Rachael that his briefcase is made of babyhide and notices that her horrified response is just a little too late.
He asks Eldon whether Rachael even knows she is an android.
As for the owl, it's artificial too. Eldon says there are no more owls.
Rick heads back to the hovercar parked on the roof. He's now come up against a Nexus-6 and knows the Voigt-Kampff empathy test works on them.