On Fifties World, Quinn's father Michael Mallory is still alive in 1996.
"Taxi Driver" reference: When Gillian is talking to Quinn in the cab, the driver asks her if she's talking to him. He says "Are you talking to me?" twice, and then says "You must be talking to me because there is nobody else here". This is a reference to Robert De Niro's famous scene in Taxi Driver where he talks to his Reflection in the mirror.
On Fifties World, it was decided that advanced technology was to the detriment of society after the atomic bombing of Hiroshima in 1945 and technology was effectively banned. This was enforced by the Bureau of Anti-Technology. By 1996, the United States' level of technology was at a 1950s level.
On Fifties World, Jonas Salk never developed the polio vaccine and the disease still ran rampant, killing thousands of people in the United States annually. One of the victims was Quinn's double.
Deanna Milligan, who plays the title character of Gillian, married actor Jason Gaffney. While not appearing in this episode, Gaffney had a recurring role in the first season as Conrad Bennish, a classmate of Quinn's (and a thorn in Arturo's side!) on their home world.