Why are the stances not the super low you see in many schools?
1) Many schools go too low. Even for stance training, you want to get the point where the rooting is greatest. If you are too high or too low your root suffers. It's all about the baby bear.
That said, the drawing still show stances that are slightly higher then optimal. Here are some theories:
1) Photography in those days didn't have instant flash. You had to hold positions for a considerable amount of time. My guess is, many pictures were taken so he might have wanted to conserve energy
2) I am told that LSW had a hernia during the photo shoot. That could explain some stuff.
Notice though, that he is able to get low on some of the shots.
Thanks Kung Lek for putting it together,