In session 18 (Speak Like a Child), it is likely that the antique electronics dealer is supposed to be watching a recording of an episode of Beverly Hills, 90210 (1990). This assumption can be made by the following clues: 1) the girl mentions how where they are are different from Minnesota, 2) the characters are twin brother and sister, and 3) the girl calls the boy "Brandon." A shot of the executive producers credits is also shown on screen but obscured by the dealer sitting in front of the television screen. However, what can be read are the names "Jason Prest..." and "Shanan D...", likely a reference to the two actors who played twin brother and sister from Minnesota, Jason Priestley and Shannen Doherty.
In Episode 18, two delivery companies arrive with packages: first, a company with a tape and a turtle logo; second and last, a company with a video player and a hare logo. It is a reference to Aesop's fable "The Tortoise and the Hare".
The trivia item below may give away important plot points.
At the beginning of episode 18, Jet tells Ed about Taro Urashima's legend (a man who ages suddenly upon opening a box). Later, they receive a tape that Faye Valentine recorded as a teen. The recording is more than 50 years old, though, revealing that Faye is much older than she looks due to cryogenic sleep.