I'm not sure how or why Bandai managed to do it, but in many ways the shots of the final versions are worse than the original colored early prototypes. The Ozma version for example doesn't look too shabby in the early prototype picture, but the final looks like it has Down Syndrome. The early version has more of a neck and the head rises above the "shoulder blades". The ankles while being too low on early one are just too high to the point of being comedic.
I was impressed with all the detail Bandai etched into the toy shown in some of the close up prototype pics, but without the supporting proportions that capture the essence of the valk, all that detail becomes moot. I mean you can say Yamato's YF-21 is not perfectly proportioned, but I don't think people were really expecting "perfect". The battroid mode's proportions do well in capturing the essence of the valkyrie as portrayed in the anime and line art in all the key places from the front and back. Bandai's 1/60 VF-25 however just doesn't seem to manage to do that, imo. Which is made even more disappointing in the knowledge that many of the compromises in proportions didn't not have to be that way as evidenced by the 1/72 model. The height of the legs with respect to the crotch piece in the model can be adjusted due to the U-shaped swing bar it appears to be using. If this was made of die-cast, there's no reason it couldn't have been used on the toy while keeping the durability aspect. Instead, they just have a straight rod coming out of the upper part of the crotch piece itself to attach the legs to.