Visible crew/equipment: When Frasier is standing through his sunroof to speak with the drivers stuck behind him in the parking garage, one shot shows Frasier's body and much of the rear window which features a very clear reflection of the boom mic.
Some Assembly Required - S10-E19
Visible crew/equipment: As Frasier and Roz are leaving the Grant's home you can see the shadow of a boom mic appear near the top of the door. It quickly comes into frame and you then see it disappear.
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.