I am not exactly sure what the pelican did, but it looked to me like it turned the pouch on the lower beak inside out! I have never seen such a thing until now! It did a lot of stretching and just before this stretched its neck up completely with that beak and pouch showing. Sometimes when just sitting one doesn't see the pouch at all. It is used for scooping up fish.

Here is what 'Projectbeak.org' has to say about it: "The American White Pelican uses its beak to scoop up fish. Sometimes, these birds will fish in semi-circular or circular groups so they can concentrate fish for easy feeding. A pelican expands the pouch on its beak when it's fishing, and sometimes when it's stretching. Otherwise, the pouch on its beak is folded up."

I learned that pelicans do indeed turn their pouch inside out. The website 'www.beautyofbirds.com' said: "pelicans perform exercises, such as stretching and turning the pouch inside out, to keep it flexible." Thanks for finding this information, Laura!