The waist of the shoe is not depending on the last, but is defined by the way the insole is cut. The outer sole will follow the insole.
In the forefoot and around the heel the last has a well defined edge (feather-edge), so there is no doubt, as to where the insole gets cut. When it comes to the waist, in particular the inside waist, there are no edges, it is rounded and soft. So it's at the shoemakers discretion where he places the cut. The narrower the waist, the more curved the line is, the more difficult the "˜making "˜ (attaching the sole) becomes. (A shoe with a narrow waist gives more support to the foot.)
Traditionally shoemakers in Central-Europe did pay very little attention to the waist. Even well-respected firms frequently produce ill-defined, sluggishly cut waists. Judging by the pictures, I have very little doubt that both pair are made on the identical last. The fact that the new shoes have a narrower waist, points either at different "˜maker', or. presuming both pairs were made by the same person, that his skill-level has improved.