They're actually the same. The one emerging just hadn't filled out yet.
I'm not sure I understand what you mean, Dave. Are you saying that you think the top photo and the second photo are the same dragonfly species?
Although I'm not great at identifying dragonflies, I'm pretty sure they are not. One way fairly easy way that you can tell is by looking at the eyes. The eyes of most dragonfly species touch in the middle. That trait is most pronounced in the Aeshnidae, and their very large eyes form a seam where they meet. That was the main reason that I suggested that your emerging dragonfly might
be in that family. (John's dragonfly is probably in the same family as yours, but I can't say if it might be same genus/species.) Beyond that, judging the genus/species of a teneral (freshly emerged) dragonfly gets a bit tricky because the color and markings that help to distinguish most adults aren't fully developed yet. In that sense, you are quite right that it hasn't filled out yet.
The dragonfly at the top, however, has smaller eyes that are much further apart. This is a trait of two common families, the Gomphidae and the Petaluridae (Petaltails). The pattern on the body of the dragonfly in the top photo looks much more like most gomphids than most petalurids to me, and that is why I suggested Gomphidae as the likely family.
Aeshnids and gomphids are very different in other ways. Gomphids tend to be stream and river dwellers. Although the dragonfly in the top photo might have come from the lake, it could also have come from a stream, and was just visiting the lake to feed.
Sorry, but when I said that I'm not good at dragonflies, I didn't mean to imply that I don't know anything about them. It's just that there are some outstanding professional aquatic entomologists who frequent this site, and I was hoping that one of them could tell you much more than I can. Taking your dragonflies to the family level is about the best that I could attempt with my limited knowledge, and I'm not sure that I have it right. But, I am as sure as I know how to be that they do belong to very different families.