Continuity mistake: In the opening scene, Roz is in Cafe Nervosa reading a children's book. Frasier comes in and she puts the book behind her, presumably into her purse which is hanging on the chair. But throughout the scene, the book is sitting on the table in front of her.
Plot hole: When Frasier is trying to get to the bottom of Niles' problem viewing Daphne in a real way, we see them both against past scenes in the show; Frasier watches and comments on some of them as he talks but because he is actually only discussing these events with Niles, he shouldn't be able to see a visual of anything such as the dress Daphne is wearing during the dance scene.
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.