Rick Deckard (Harrison Ford) is a police special operative known as a Blade Runner. His job is to hunt down replicants, which are genetically engineered organic robots who have been banished from Earth to the "off-world" colonies.
In this scene (at the 11:45 mark) Rick is summoned to his supervisor Bryant's (M. Emmet Walsh) office and is given an assignment to eliminate four escaped replicants. They discuss the case over two shots of Johnnie Walker Black Label.
This bottle has become a bit of a cult classic itself.