Karen mentions Niles from the fellow NBC series, Frasier. Like Niles, Karen is also married to a character who is unseen by the audience but is described in ridiculous and unrealistic terms. The only difference is that Niles' wife, Maris, is described as overly skinny, and Karen's husband, Stanley, is described as morbidly obese.
Throughout the episode, James tries to get Grace to come look at the moon. On March 1, 2018 - the evening this episode aired - there was actually a full moon.