Flat.
Compare this bird's crop with a few of your other birds crops in the morning.
You'll notice or feel if it is not empty compared to your other birds.
Then your bird does not have an impacted crop.
Impacted crop and sour crop are two different things.
It's possible your bird just drank too much at that exact time you saw it lean over.
I asked you to check its crop first thing in the morning, there is a reason for this so please do it...
This is written by a veterinarian not a blogger:
https://zupreem.com/avian/toxic-foods-your-bird-should-never-eat/#:~:text=However%2C%20while%20these%20spicy%20veggies,birds%2C%20cats%2C%20and%20dogs.&text=Garlic%20contains%20allicin%2C%20another%20chemical,anemia%20and%20weakness%20in%20birds.