When the phenotype is the genotype there is no difference - I explained this before.
Why not?
You can still randomly alter the phenotype/genotype, and select the next generation from the best population, as in a darwinian analogue, or you could direct the changes in a certain direction, and not really bother with selection, as proposed by Lamarck.
Only one works in biology, but conceptually both could.
Anyway surely in technical develop,ent the genotype analogue is the blueprint, whilst the phenotype analgue is the actual product.
I develop a transistor and find that the first iteration has too low a blocking voltage, an a resistance that is lower than I need. My next iteration will be to raise both, either by increasing the length of the drift-region or by reducing its conductivity. In an evolutionary approach, the next iteration is just as likely to be worse as better, the worse ones just would not get selected.