Classic view of a M. sexta adult.
One of the things you'll most likely notice is that the animal no longer looks like a caterpillar (well, ok, it looks a bit like a caterpillar with wings from the top, but it's a stretch). No longer do we find the soft, hairless body, prolegs, and very hardened, obvious head capsule of the larva. The caterpillar has lost its hardened mandibles that are adapted for consuming leaves, and has instead grown a long proboscis that it uses to drink nectar, which you can see in the image below.
A M. sexta adult seen from the bottom/side.
The caterpillars did not have large, noticeable eyes, and realistically don't need large eyes to survive (they live on their food, and do little but eat). However, the adults moths fly, primarily at night, and thus their compound eyes are much larger.
From the top it can look like the moths have only two wings (one pair), but they actually have four wings (two pairs). The picture below shows the two pairs relatively clearly - the larger pair that lies on top are the forewings, while the smaller pair that are held underneath are the hindwings. In the first picture I posted (the top view) the hindwings are visible near the middle two yellow/orange dots on the abdomen.
A M. sexta adult from the bottom, showing its two pairs of wings.
After eclosing, the adults would normally find and mate with a member of the opposite sex, and then the female would lay fertilized eggs on suitable host plants. I don't have a setup capable of keeping adult moths happy enough to mate, and thus this post completes my Manduca sexta development series. I hope you've enjoyed it!
More pictures of the M. sexta adult - larger versions are on Flickr.
Note: While I was collecting tomato leaves for my M. sexta caterpillars, I collected some caterpillars from the wild and reared them as well. Thus, it is possible that this moth is a Manduca quinquemaculata, whose range overlaps that of M. sexta in this region; adults of the two species look quite similar.