In the photo album Rory brings down to show Richard and Emily, the picture of Emily's sister Hopie is actually a photo of Kelly Bishop (the actress who plays Emily).
Trapped at her grandparents' house in the snow storm, Rory finds a photo album that gets Emily and Richard reminiscing. Richard mentions Emily's fascination with Errol Flynn saying that Emily had even tried to get him to grow a moustache like Flynn's. In later seasons Richard actually grows a moustache just like Errol Flynn's that Emily detests, and it becomes a point of contention between them.
This is one of the rare episodes to feature all the main characters in one episode.
In the heart to heart scene where Lorelai and Lane discuss Lane's boy problems while Rory is stuck in Hartford, you can see that the wardrobe designer has cut Lane's jeans down the back. Lauren Graham writes in one of her books that this is common practice when trying to get a pair of pants to fit an actor.
Ironically, the doll house in Lorelei's old bedroom is a slightly grander version of the house that she and Rory actually live in. Fans have debated on whether there is any symbolism implied by the writers, and it will be involved in later episodes.