When Karen was at Will and Grace's flat with Jack babysitting the puppy, she puts her cocktail glass down on the table, but when Will and Grace come back from the movie it's no longer there.
When Will and Grace go and see a movie you can hear some of the Titanic theme song, but when they get back Grace mentions that Will couldn't even sit through a ninety minute movie. Titanic is more then a ninety minute movie, in fact it is about twice that.
In this episode, much is made about Will not being a dog person, but in a later season much is made about a dog he had and loved when he was a boy.
When Grace is trying to persuade Will to come out to the cinema with her.