It's somewhat ineffective

[shishir_2625]

The AI doesn't listen even when I put my words in all capitals. For example, if I say the peacocks beak is VERY WIDE OPEN, it will still give me a closed beak. It doesn't seem to work very well.

[Kevin Stohlmeyer]

@shishir_2625 shouting at the AI (writing in all caps) has no effect on any model including Firefly. This page may help with writing more effective prompts:

https://helpx.adobe.com/firefly/using/tips-and-tricks.html

"Peacock standing in a shallow pond it's beak is open"

[DeanUtian]

Firefly does not differentiate between words in lowercase vs uppercase. The term 'very' may not have much value either. 
I tried 'peacock with beak open' and most of the generated results had the beak closed. I tried 'side view of peacock with beak open' and got better results.
Sometimes a slight variation of the prompt can get better results.