I like this!
But I think you're wrong about the limit. A scenario by default includes reality around it, in this case our world. I would also like to distinguish between unexpected changes, which each range from 0‽ (no measurable change) to 1‽ (a change to approximately the least relevant object possible), and abstractions, which have the same range. A picture is an example of an abstraction. Changes to the self are both changes and abstractions. Abstractions of the self count double.
In no particular order:
Expected action: I am given a hamburger.
0‽: I receive a hamburger. There is nothing unusual or special about it. Nothing else of importance happens.
0.2‽: I receive a sandwich. (There is a change to the expected situation in one way, and it's partial)
1‽: I receive a raccoon. (One complete change to the situation, in this case the direct object)
1‽: I receive a hamburger from a raccoon. Although it wasn't stated, I expected to receive that burger from a person.
1.2‽: I receive a sandwich from a raccoon. There is a nearly-full change to the subject (human —> raccoon) and a slight change to the object (burger —> sandwich)
1‽: I receive a picture of a hamburger. Getting a depiction instead of an object adds 1‽ for abstraction.
2‽: I receive a picture of a raccoon. The object is changed and abstracted.
1‽: A raccoon receives a hamburger. The recipient is changed.
2‽: I am turned into a raccoon, and receive a hamburger.
1‽: A nearby portrait of me receives a hamburger.
2‽: I become a picture of myself, and receive a hamburger.
3‽: I become a raccoon, and receive a picture of a hamburger.
5‽: I become a picture of a raccoon, and receive a picture of a skateboard.
Problem: levels are gained too easily.
Solution proposal: Stop counting abstractions and changes separately. A picture of a raccoon is no more random or surreal than an actual raccoon, if you expect a hamburger. Only one abstraction can be used on a part of a scenario. This fits well with changes.
1‽: A portrait of me receives a hamburger.
1‽: A picture of a picture of a song about a raccoon receives a hamburger.
2‽: A raccoon receives a picture of a hamburger.
2‽: A raccoon receives a skateboard.
2‽: A raccoon receives a picture of a skateboard.
NOTE: ^ and ^^^ have the same rating, because a pic of a hamburger has 1‽ due to abstraction and a pic of a skateboard has 1‽ due to being completely unrelated. The abstraction doesn't matter, because you aren't abstracting part of the original expectation.
Let's start over, with the new system:
Expected action: I am given a hamburger.
0‽: I receive a hamburger. There is nothing unusual or special about it. Nothing else of importance happens.
0.2‽: I receive a sandwich. (There is a change to the expected situation in one way, and it's partial)
1‽: I receive a raccoon. (One complete change to the situation, in this case the direct object)
1‽: I receive a hamburger from a raccoon. Although it wasn't stated, I expected to receive that burger from a person.
1.2‽: I receive a sandwich from a raccoon. There is a nearly-full change to the subject (human —> raccoon) and a slight change to the object (burger —> sandwich)
1‽: I receive a picture of a hamburger. Getting a depiction instead of an object adds 1‽ for abstraction.
1‽: I receive a picture of a raccoon. The object is changed and abstracted. change overrides abstraction!
1‽: A raccoon receives a hamburger. The recipient is changed.
2‽: I am turned into a raccoon, and receive a hamburger.
1‽: A nearby portrait of me receives a hamburger.
2‽: I become a picture of myself, and receive a hamburger.
3‽: I become a raccoon, and receive a picture of a hamburger.
3‽: I become a picture of a raccoon, and receive a picture of a skateboard. (2‽ due to a complete change to myself, and 1‽ due to a complete change to the burger)
4‽: I become a raccoon, and receive a skateboard from a hamburger.
5‽: I become a portrait, and a raccoon receives a skateboard from Betamax.
7‽: I become a portrait, and a clone of myself is beaten with a skateboard by a raccoon while it literally rains cats and dogs. (complete change to the weather! I didn't say so, but normal weather was expected. The action is also changed from giving to beating.)
10‽: I become a raccoon, and a clone is beaten with a skateboard by a portrait of a cow while it rains cats and dogs, but the robot landlord evicts us for huffing kittens. (previous + unexpected eviction, which itself has 2‽ for a robo-landlord and for the impossibility of kitten-huffing)
I think this works well, but I don't have any way to deal with recursion or reference to a different part of a scene.
Example:
?‽: I receive a picture of myself.
?‽: A clone of myself receives a picture of me receiving a raccoon.