Revealing mistake: When Frasier drives into and breaks the barrier at the parking garage, you can see that the barrier snaps very cleanly at an obviously pre-cut point.
Revealing mistake: When Frasier and his guest are standing up to leave, the girl behind the counter is watching them for her cue to come over.
Revealing mistake: Even though she has customers in front of her, the barista can be seen watching Frasier and his guest as they are talking, so she can see her cue to come over.
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.