Any ideas what this means?! Hens puffed feathers

[colette peters]

Any suggestions what this characteristic means??
So this is Joe (female) for Jolene, she’s about 3.5, stopped laying a year now she’s super healthy, but notice in the last month her rear feathers stay puffed up. She’s not molting and not sure what this means?

I just cleared and killed the coop mite infestation that’s now mite free
But could this feather thing be mites nesting in her legs that’s an issue?

@Texas Kiki