Question about the equivalent circuit of an induction motor
What is the significance in the discrepancy between R2/s and
  R2[(1-s)/s]?


R2/s = R2 + R2[(1-s)/s]

The power dissipated in R2/s is the total power developed in the rotor. The power in R2 is dissipated as heat in the rotor. The power in R2[(1-s)/s] is electrical power converted to mechanical power.

Breaking R2/s into two parts more clearly illustrates what happens to the power developed in the rotor.