Again, we're looking for a good definition for explaining it to laypeople, and I don't find it that difficult. "Pulling a slot machine" or the one from the "solving Sudokus" both work pretty well.
The theoretical mathematician definition isn't very good either because I think enough people get that the novelty has some kind of inherent value that doing something repetitive like the above does not?
> valuable, i.e. relays no additional useful information about the world (e.g. the boiling point of some new liquid or something)
Theoretical mathematicians don't provide anything useful according to your definition.