I guess as we gain more experience in this wonderful world of womenswear we are constantly learning and adapting. And on of these learning curves is with panties. We are all different shapes and sizes in that area. When I first started yes I think the prettiness was the main factor but quickly got to realise that the, let’s say, sexiest is seldom the most comfortable, less material, perhaps more scope for discomfort (do you really want a string up there all day!).
Now it’s so much fun looking for panties with both comfort and prettiness, and they are out there. I guess it’s just trial and error, and getting an eye for your size, coverage, favourite materials and of course some femininity.
And I guess GGs like you wife have had a whole lifetime to come to this conclusion.