Roz's Turn - S4-E17
Revealing mistake: Bebe is in the booth telling Frasier how she misunderstood him about Roz. As she says "wink", we can see Frasier's reflection in the booth's glass - his head bobs up. The next shot we see, though, is of Frasier's head bobbing up - shot at the same time, we just see it a split second later.
Answer: In the last episode, they explained that Tossed Salad and Scrambled Eggs is a metaphor for the mixed-up people to whom Frasier dispenses his radio psychiatric advice.