The riff: Observed and pointed out by Joel as a large crowd of skaters enjoy some of the short’s titular snow thrills on a large ice rink.
The explanation: He’s referring to the classic 1970 romantic drama “Love Story,” which starred O’Neal and MacGraw as lovers from different social classes who are doomed by MacGraw’s tragic illness. During one of many montages of their developing relationship, they go skating and frolicking in the snow while a famous portion of the Oscar-winning soundtrack plays. Both O’Neal and MacGraw were nominated for Academy Awards for their roles, but neither won.
Novelty factor: I’ve never actually seen “Love Story,” but I suspected this was the source of the riff as soon as Joel followed it up with “Love means never having to watch this movie.”