The first term is a constant contribution to the free energy, and can be ignored. The second term is a finite shift in "t". The third term is a quantity that scales to zero at long distances. This means that when analyzing the scaling of "t" by dimensional analysis, it is the shifted "t" that is important. This was historically very confusing, because the shift in "t" at any finite "λ" is finite, but near the transition "t" is very small. The fractional change in "t" is very large, and in units where "t" is fixed the shift looks infinite.