While visiting the Tunt manor, Cheryl mentions that she has a pet ocelot named Babou. This is a reference to the Spanish surrealist painter Salvador Dalí, who was well known for owning and frequently traveling with his pet ocelot Babou.
When ISIS traces the phone call, the coordinates shown are N33.806333 W84.344165, which corresponds to 1123 Zonolite Road Northeast in Atlanta, Georgia; this is the address for Floataway Cafe.
The helmet worn by Cheryl has a peace-symbol button on it, likely a reference to Full Metal Jacket (1987).
The voice identification system identifies Brett as Brett Buckley. In Archer Vice: White Elephant (2014), he will be referred to as Brett Bunsen.