I can speak some chicken, but I do not know what this means. What does it sound like she is saying here? I thought it was "I want to lay an egg" but she makes this sound in the evening sometimes too.
For mine, it has always meant, "I'm getting close to laying an egg."
Possibly, "I'm getting close to laying an egg so get out of the way" since it is nearly always done when her preferred nest is already in use. For the first few days of their laying when they were pullets just beginning to lay it was also done when the nests were empty.
I have a coop/run combo so they never wait to go in or out. So I wouldn't know if it also means "get out of my way" separate from needing to lay an egg.