Proof by existence?
https://gist.github.com/nlothian/50241d34a654fcf0caa280d4475...
Looks pretty good to me. ChatGPT in "Thinking" model.
Edit: I've added the Opus version on the same link.
Neither of those are from 'under' they both look either front or top?
Imagine yourself under the ducks feet, looking up at an oblique angle - wings as I suggested. The AI won't do that, it has no reference for dimensionality.
I live near an area with lots of pelicans. If you look up at one flying overhead this is what they look like.
Here is a photo for comparison: https://commons.wikimedia.org/wiki/File:American_white_pelic...
They look similar to the photo, but meet the instructions better ("from underneath").
What are you expecting exactly?