Visible crew/equipment: When Frasier and Daphne are sitting talking in the sitting room, Frasier stands and the camera angle shows the fake wall above the fireplace - you can see the flue and that the wall stops just over where the shot normally finishes. There is visibly no proper wall behind the fireplace, you can see clear through to the construction behind.
Visible crew/equipment: When Frasier is getting ready to leave his booth while Bulldog starts his show, through the door on the left we can see a fairly thick white cable suspended in the air. It is visible for a couple of shots, but when Frasier opens the door to leave, it is gone.
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.