There are often many ways of modelling a problem. Consider the famous "SEND + MORE = MONEY" example:

sendmore(Digits) :- Digits = [S,E,N,D,M,O,R,Y], Digits :: [0..9], alldifferent(Digits), S # |

An alternative model is based on the classical decimal addition algorithm with carries:

sendmore(Digits) :- Digits = [S,E,N,D,M,O,R,Y], Digits :: [0..9], Carries = [C1,C2,C3,C4], Carries :: [0..1], alldifferent(Digits), S # |

Both models work fine, but obviously involve different variables and constraints. Even though high-level models reduce the need for finding sophisticated encodings of problems, finding good models still requires substantial expertise and experience.