A "Tomato Surprise" is a story where the whole point of the plot is the revelation of some detail that has been deliberately hidden from the reader/viewer, which if it were known from the beginning would have made the whole story moot. The tongue-in-cheek example given in the writer's guide I mentioned above is hiding the fact that the narrator is a tomato until the last sentence. Most of the time it's a cheap gimmick that carries a bad story along, but sometimes it can make for a good story -- witness that one Twilight Zone ep from the POV of a plastic surgery patient, whose vision is blurry (keeping us from clearly seeing the people around her), who is hoping that her procedure has fixed her terrible ugliness. Sadly, we learn it hasn't. The Tomato Surprise at the end is that she is beautiful by our standards, but the race into which she was born all have deformed pig-faces.
A "Tomato In The Mirror" is when the Tomato Surprise is about a character but is hidden from the character himself, and he finds it out usually as part of the climax of the story. There was a 1950s B movie about androids replacing humans ("Attack of the Humanoids" or something like that, maybe?), where at the end the hero discovers that he, too, is an android but didn't know it -- classic Tomato In The Mirror.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.
A "Tomato In The Mirror" is when the Tomato Surprise is about a character but is hidden from the character himself, and he finds it out usually as part of the climax of the story. There was a 1950s B movie about androids replacing humans ("Attack of the Humanoids" or something like that, maybe?), where at the end the hero discovers that he, too, is an android but didn't know it -- classic Tomato In The Mirror.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.